Document And Entity Information (USD $) In Billions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Jan. 31, 2013	Jun. 29, 2012
Document Information [Line Items]
Entity Registrant Name	SEI INVESTMENTS CO
Entity Central Index Key	0000350894
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2012
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	FY
Trading Symbol	SEIC
Amendment Flag	false
Entity Common Stock, Shares Outstanding		172,642,438
Entity Public Float			$ 2.7
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes

Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current Assets:
Cash and cash equivalents	$ 452,247	$ 420,986
Restricted cash	6,000	6,000
Receivables from regulated investment companies	31,084	25,800
Receivables, net of allowance for doubtful accounts of $805 and $924 (Note 4)	171,734	142,109
Deferred income taxes, net	2,012	1,150
Securities owned	20,088	20,949
Other current assets	18,239	17,957
Total Current Assets	701,404	634,951
Property and Equipment, net of accumulated depreciation of $201,418 and $182,453 (Note 4)	127,581	129,548
Capitalized Software, net of accumulated amortization of $149,747 and $117,100	307,490	309,133
Investments Available for Sale (Note 6)	75,869	83,008
Trading Securities (Note 6)	5,909	56,325
Investment in Unconsolidated Affiliates (Note 2)	77,398	68,454
Other Assets, net	14,173	13,140
Total Assets	1,309,824	1,294,559
Current Liabilities:
Accounts payable	11,248	1,999
Accrued liabilities (Note 4)	138,305	147,044
Deferred revenue	2,452	2,030
Total Current Liabilities	152,005	151,073
Deferred Income Taxes	93,458	93,751
Other Long-term Liabilities (Note 12)	7,032	8,276
Total Liabilities	252,495	253,100
Commitments and Contingencies (Note 11)
SEI Investments shareholders' equity:
Series Preferred stock, $.05 par value, 50 shares authorized; no shares issued and outstanding	0	0
Common stock, $.01 par value, 750,000 shares authorized; 172,220 and 176,506 shares issued and outstanding	1,722	1,765
Capital in excess of par value	624,305	577,949
Retained earnings	405,914	443,702
Accumulated other comprehensive income, net	6,239	1,900
Total SEI Investments Shareholders’ Equity	1,038,180	1,025,316
Noncontrolling Interest	19,149	16,143
Total Equity	1,057,329	1,041,459
Total Liabilities and Equity	$ 1,309,824	$ 1,294,559

Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current Assets:
Receivables, allowance for doubtful accounts	$ 805	$ 924
Property and Equipment, accumulated depreciation	201,418	182,453
Capitalized Software, accumulated amortization	$ 149,747	$ 117,100
Stockholders' Equity:
Series Preferred stock, par value	$ 0.05	$ 0.05
Series Preferred stock, shares authorized	50	50
Series Preferred stock, shares issued	0	0
Series Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	750,000	750,000
Common stock, shares issued	172,220	176,506
Common stock, shares outstanding	172,220	176,506

Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenues:
Asset management, administration and distribution fees	$ 723,630	$ 669,788	$ 628,535
Information processing and software servicing fees	236,190	222,417	231,529
Transaction-based and trade execution fees	32,702	37,522	40,771
Total revenues	992,522	929,727	900,835
Expenses:
Subadvisory, distribution and other asset management costs	106,048	103,134	101,722
Software royalties and other information processing costs	26,722	27,437	24,419
Brokerage commissions	23,889	27,022	28,882
Compensation, benefits and other personnel	335,296	289,445	269,165
Stock-based compensation	15,736	14,112	26,783
Consulting, outsourcing and professional fees	109,828	113,171	89,033
Data processing and computer related	46,617	47,003	41,064
Facilities, supplies and other costs	60,976	55,579	56,284
Amortization	33,258	27,288	24,048
Depreciation	22,586	21,471	21,902
Total Expenses	780,956	725,662	683,302
Income from operations	211,566	204,065	217,533
Net gain from investments	14,067	3,360	48,533
Interest and dividend income	5,696	5,829	6,326
Interest expense	(504)	(585)	(1,478)
Other expense, net	0	0	(590)
Equity in earnings of unconsolidated affiliates	98,671	105,818	99,457
Net income before income taxes	329,496	318,487	369,781
Income taxes	121,462	111,837	136,461
Net income	208,034	206,650	233,320
Less: Net income attributable to the noncontrolling interest	(1,186)	(1,691)	(1,633)
Net income attributable to SEI Investments Company	$ 206,848	$ 204,959	$ 231,687
Basic earnings per common share	$ 1.19	$ 1.12	$ 1.23
Basic earnings per common share, shares	174,295	182,547	188,468
Diluted earnings per common share	$ 1.18	$ 1.11	$ 1.22
Diluted earnings per common share, shares	175,872	184,127	190,321
Dividends declared per common share	$ 0.63	$ 0.27	$ 0.20

Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Statement of Other Comprehensive Income [Abstract]
Net income	$ 208,034	$ 206,650	$ 233,320
Other comprehensive income, net of tax:
Foreign currency translation adjustments	5,904	(3,195)	2,205
Unrealized holding loss on investments:
Unrealized holding gains during the period, net of income taxes of $86, $811 and $486	341	1,369	484
Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, Net of Income Taxes of $50, $77 and $56	(86)	(134)	(105)
Total other comprehensive income, net of tax	6,159	(1,960)	2,584
Comprehensive income	214,193	204,690	235,904
Comprehensive income attributable to the noncontrolling interest	(3,006)	(988)	(2,318)
Comprehensive income attributable to SEI Investments Company	$ 211,187	$ 203,702	$ 233,586

Consolidated Statements Of Comprehensive Income (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Statement of Other Comprehensive Income [Abstract]
Unrealized holding gains (losses) during the period, income tax expense	$ 86	$ 811	$ 486
Reclassification adjustment for gains realized in net income, income tax expense	$ 50	$ 77	$ 56

- Definition

Tax effect of the income statement impact of the reclassification adjustment for unrealized gain (loss) realized upon the sale of available-for-sale securities.

+ References+ Details

- Definition

Tax effect of unrealized holding gain (loss) before reclassification adjustments and transfers on available-for-sale securities.

+ References+ Details

Consolidated Statements Of Changes In Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock [Member]	Capital In Excess Of Par Value [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	SEI Investments Company [Member]	Noncontrolling Interest [Member]
Beginning balance at Dec. 31, 2009		$ 1,902	$ 522,080	$ 384,483	$ 1,258
Beginning balance, shares at Dec. 31, 2009		190,208,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to SEI	231,687			231,687
Purchase and retirement of common stock		(58)	(13,426)	(107,498)
Purchase and retirement of common stock, shares	5,814,000	(5,814,000)
Issuance of common stock under the employee stock purchase plan		1	1,902
Issuance of common stock under the employee stock purchase plan, shares		114,000
Issuance of common stock upon exercise of stock options		16	26,177
Issuance of common stock upon exercise of stock options, shares	(1,633,000)	1,633,000
Stock-based compensation	26,783		26,783
Tax benefit on stock options exercised			1,877
Dividends declared	37,513			(37,513)
Other comprehensive (loss) income	2,584				1,899
Total SEI Investments Shareholders' Equity						1,041,570
Noncontrolling Interest	15,155						15,155
Total Equity at Dec. 31, 2010	1,056,725	1,861	565,393	471,159	3,157
Ending balance, shares at Dec. 31, 2010		186,141,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to SEI	204,959			204,959
Purchase and retirement of common stock		(111)	(27,196)	(183,858)
Purchase and retirement of common stock, shares	11,109,000	(11,109,000)
Issuance of common stock under the employee stock purchase plan		1	1,892
Issuance of common stock under the employee stock purchase plan, shares		110,000
Issuance of common stock upon exercise of stock options		14	22,314
Issuance of common stock upon exercise of stock options, shares	(1,364,000)	1,364,000
Stock-based compensation	14,112		14,112
Tax benefit on stock options exercised			1,434
Dividends declared	48,558			(48,558)
Other comprehensive (loss) income	(1,960)				(1,257)
Total SEI Investments Shareholders' Equity	1,025,316					1,025,316
Noncontrolling Interest	16,143						16,143
Total Equity at Dec. 31, 2011	1,041,459	1,765	577,949	443,702	1,900
Ending balance, shares at Dec. 31, 2011	176,506,000	176,506,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to SEI	206,848			206,848
Purchase and retirement of common stock		(75)	(19,370)	(135,819)
Purchase and retirement of common stock, shares	7,528,000	(7,528,000)
Issuance of common stock under the employee stock purchase plan		1	1,794
Issuance of common stock under the employee stock purchase plan, shares	11,580,000	105,000
Issuance of common stock upon exercise of stock options		31	47,613
Issuance of common stock upon exercise of stock options, shares	(3,136,000)	3,137,000
Stock-based compensation	15,736		15,736
Tax benefit on stock options exercised			583
Dividends declared	108,817			(108,817)
Other comprehensive (loss) income	6,159				4,339
Total SEI Investments Shareholders' Equity	1,038,180					1,038,180
Noncontrolling Interest	19,149						19,149
Total Equity at Dec. 31, 2012	$ 1,057,329	$ 1,722	$ 624,305	$ 405,914	$ 6,239
Ending balance, shares at Dec. 31, 2012	172,220,000	172,220,000

Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities:
Net income	$ 208,034	$ 206,650	$ 233,320
Depreciation	22,586	21,471	21,902
Amortization	33,258	27,288	24,048
Equity in earnings of unconsolidated affiliates	(98,671)	(105,818)	(99,457)
Distributions received from unconsolidated affiliate	92,227	109,273	72,060
Stock-based compensation	15,736	14,112	26,783
Provision for losses on receivables	(119)	(271)	(1,004)
Deferred income tax expense	(1,191)	1,001	6,461
Net realized gains from investments	(14,067)	(3,360)	(48,533)
Change in other long-term liabilities	(1,244)	2,631	(81)
Change in other assets	(619)	315	(379)
Other	6,680	(3,148)	2,852
Increase (Decrease) in Restricted cash for broker-dealer operations	0	0	(16,000)
Increase (Decrease) in Receivables from regulated investment companies	5,284	(3,482)	1,148
Increase (Decrease) in Receivables	30,852	11,474	11,032
Increase (Decrease) in Other Current Assets	282	1,689	1,101
Increase (Decrease) in Accounts Payable	9,249	(2,583)	1,734
Increase (Decrease) in Accrued Liabilities	21,627	(1,340)	(13,847)
Increase (Decrease) in Deferred Revenue	422	422	748
Adjustments to reconcile net income to net cash provided by operating activities	49,456	50,312	(3,994)
Net cash provided by operating activities	257,490	256,962	229,326
Cash flows from investing activities:
Additions to restricted cash	0	(2,000)	0
Additions to property and equipment	(23,070)	(12,271)	(13,611)
Additions to capitalized software	(31,004)	(40,954)	(38,729)
Purchases of marketable securities	(33,662)	(73,960)	(39,085)
Prepayments and maturities of marketable securities	53,352	61,582	58,174
Sales of marketable securities	54,830	38,247	28,859
Purchases of other investments	(3,819)	(7,500)	0
Sales of other investments	0	4,906	0
LSV and LSV Employee Group cash balances, net (A)	0	0	(37,083)
Net cash provided by (used in) investing activities	16,627	(31,950)	(41,475)
Cash flows from financing activities:
Payments on long-term debt	0	(95,000)	(138,000)
Purchase and retirement of common stock	(157,543)	(208,932)	(119,775)
Proceeds from issuance of common stock	49,439	24,221	28,096
Tax benefit on stock options exercised	583	1,434	1,877
Payment of dividends	(135,335)	(22,041)	(54,634)
Net cash used in financing activities	(242,856)	(300,318)	(282,436)
Net increase (decrease) in cash and cash equivalents	31,261	(75,306)	(94,585)
Cash and cash equivalents, beginning of period	420,986	496,292	590,877
Cash and cash equivalents, end of period	452,247	420,986	496,292
Interest Paid	367	559	1,488
Income Taxes Paid	113,160	116,483	145,553
Dividends Payable	$ 0	$ 26,518	$ 0

Summary Of Significant Accounting Policies

12 Months Ended

Dec. 31, 2012

Accounting Policies [Abstract]

Summary Of Significant Accounting Policies

Summary of Significant Accounting Policies

Nature of Operations

SEI Investments Company (the Company), a Pennsylvania corporation, provides investment processing, investment management, and investment operations solutions to corporations, financial institutions, financial advisors, and ultra-high-net-worth families in the United States, Canada, the United Kingdom, continental Europe, and other various locations throughout the world. Investment processing solutions consist of application and business process outsourcing services, professional services and transaction-based services. Revenues from investment processing solutions are recognized in Information processing and software servicing fees on the accompanying Consolidated Statements of Operations, except for fees earned associated with trade execution services.

Investment management programs consist of mutual funds, alternative investments and separate accounts. These include a series of money market, equity, fixed-income and alternative investment portfolios, primarily in the form of registered investment companies. The Company serves as the administrator and investment advisor for many of these products. Revenues from investment management programs are recognized in Asset management, administration and distribution fees on the accompanying Consolidated Statements of Operations.

Investment operations solutions offer investment managers support for traditional investment products such as mutual funds, collective investment trusts, exchange-traded funds, and institutional and separate accounts, by providing outsourcing services including fund and investment accounting, administration, reconciliation, investor servicing and client reporting. These solutions also provide support to managers focused on alternative investments who manage hedge funds, funds of hedge funds, private equity funds and real estate funds, across registered, partnership and separate account structures domiciled in the United States and overseas. Revenues from investment operations solutions are recognized in Asset management, administration and distribution fees on the accompanying Consolidated Statements of Operations.

Principles of Consolidation

The Consolidated Financial Statements include the accounts of the Company and its wholly-owned subsidiaries and entities in which it holds a controlling financial interest. The Company determines whether it has a controlling financial interest either by its decision-making ability through voting interests or by the extent of the Company’s participation in the economic risks and rewards of the entity through variable interests. The Company accounts for noncontrolling interests in consolidated entities for which the Company’s controlling financial interest is less than 100 percent. The Company’s principal subsidiaries are SEI Investments Distribution Co. (SIDCO), SEI Investments Management Corporation (SIMC), SEI Private Trust Company (SPTC), SEI Global Services, Inc. (SGSI) and SEI Investments (Europe) Limited (SIEL). All intercompany accounts and transactions have been eliminated.

The Company accounts for investments in unconsolidated entities that are 20 percent to 50 percent owned or are 20 percent or less owned and have the ability to exercise significant influence over the operating and financial policies of the entity under the equity method of accounting. Under this method of accounting, the Company’s interest in the net assets of unconsolidated entities is reflected in Investment in unconsolidated affiliates on the accompanying Consolidated Balance Sheet and its interest in the earnings or losses of unconsolidated entities is reflected in Equity in earnings of unconsolidated affiliates on the accompanying Consolidated Statement of Operations.

Variable Interest Entities

The Company has involvement with various variable interest entities (VIE or VIEs). These VIEs consist of LSV Employee Group II, LLC (LSV Employee Group II), LSV Employee Group III, LLC (LSV Employee Group III) and investment products established for clients created in the form of various types of legal entity structures. According to the most recent accounting guidance issued by the Financial Accounting Standards Board (FASB), the determination of whether a company is required to consolidate an entity is based on, among other things, an entity’s purpose and design, a company’s ability to direct the activities of the entity that most significantly impact the entity’s economic performance, and whether a company is obligated to absorb losses or receive benefits that could be potentially significant to the entity. The guidance requires ongoing reassessments of whether an enterprise is the primary beneficiary of a VIE and requires disclosures about an enterprises involvement in VIEs.

The FASB deferred the accounting guidance for certain types of investment entities. The deferral allows asset managers that have no obligation to fund potentially significant losses of an investment entity to continue to apply the previous guidance to investment entities that have attributes of entities defined in the “Investment Company Guide.” The deferral applies to many mutual funds, hedge funds, private equity funds, venture capital and certain other types of entities. Also, money market funds subject to rule 2a-7 of the Investment Company Act of 1940 qualify for deferral. However, the deferral does not apply to the new disclosure requirements. All of the Company’s investment products where the Company is the sponsor and/or investment manager that are VIEs qualify for the deferral; therefore, the Company will continue to apply the previous guidance for the consolidation of VIEs (See Note 3).

Management’s Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Revenue Recognition

The Company’s principal sources of revenues are: (1) asset management, administration and distribution fees earned based upon a contractual percentage of net assets under management or administration; (2) information processing and software servicing fees that are either recurring and primarily earned based upon the number of trust accounts being serviced or non-recurring and based upon project-oriented contractual agreements related to client implementations; and (3) transaction-based fees for providing trade-execution services. The Company’s revenues are based on contractual arrangements. Revenues are recognized in the periods in which the related services are performed provided that persuasive evidence of an agreement exists, the fee is fixed or determinable, and collectibility is reasonably assured. Cash received by the Company in advance of the performance of services is deferred and recognized as revenue when earned. Reimbursements received for out-of-pocket expenses incurred are recorded as revenue. Certain portions of the Company’s revenues require management’s consideration of the nature of the client relationship in determining whether to recognize as revenue the gross amount billed or net amount retained after payments are made to suppliers for certain services related to the product or service offering.

Cash and Cash Equivalents

The Company considers investment instruments purchased with an original maturity of three months or less to be cash equivalents. Cash and cash equivalents include $247,314 and $281,760 at December 31, 2012 and 2011, respectively, primarily invested in SEI-sponsored open-ended money market mutual funds.

Restricted Cash

Restricted cash includes $5,000 at December 31, 2012 and 2011 segregated for regulatory purposes related to trade-execution services conducted by SIEL. Restricted cash also includes $1,000 at December 31, 2012 and 2011 segregated in special reserve accounts for the benefit of SIDCO customers in accordance with certain rules established by the Securities and Exchange Commission for broker-dealers.

Allowances for Doubtful Accounts

The Company provides an allowance for doubtful accounts equal to the estimated uncollectible amounts. The Company’s estimate is based on historical collection experience and a review of the current status of trade accounts receivable.

Concentration of Credit Risk

Financial instruments which potentially expose the Company to concentrations of credit risk consist primarily of cash equivalents and trade receivables. Cash equivalents are principally invested in short-term money market funds or placed with major banks and high-credit qualified financial institutions. Cash deposits maintained with institutions are in excess of federally insured limits. Concentrations of credit risk with respect to our receivables are limited due to the large number of clients and their dispersion across geographic areas. No single group or customer represents greater than ten percent of total accounts receivable.

Property and Equipment

Property and Equipment are recorded at cost. Expenditures for major additions and improvements are capitalized and minor replacements, maintenance, and repairs are charged to expense as incurred. Construction in progress includes the cost of construction and other direct costs attributable to the construction. When property and equipment are retired or disposed of, the related cost and accumulated depreciation are removed from the accounts and any resulting gain or loss is included in the results of operations for the respective period. Depreciation is provided over the estimated useful lives using the straight line method for financial statement purposes. No provision for depreciation is made for construction in progress until such time as the relevant assets are completed and put into service. The Company uses other depreciation methods, generally accelerated, for tax purposes where appropriate. Buildings and building improvements are depreciated over 25 to 39 years. Equipment, purchased software and furniture and fixtures have useful lives ranging from 3 to 5 years. Amortization of leasehold improvements is computed using the straight line method over the shorter of the remaining lease term or the estimated useful lives of the improvements.

Marketable Securities

The classification of investments in marketable securities is determined at the time of purchase and reevaluated at each balance sheet date. Debt and equity securities classified as available-for-sale are reported at fair value as determined by the most recently traded price of each security at the balance sheet date. Unrealized gains and losses, net of income taxes, are reported as a separate component of comprehensive income. SIDCO, the Company’s broker-dealer subsidiary, reports changes in fair value of marketable securities through current period earnings due to specialized accounting practices related to investments by broker-dealers. The Company records all of its trading securities on the accompanying Consolidated Balance Sheets at fair value. Unrealized gains and losses from the change in fair value of these securities are recognized in current period earnings. The specific identification method is used to compute the realized gains and losses on all of the Company’s marketable securities (See Note 6).

The Company evaluates the realizable value of its marketable securities on a quarterly basis. In the event that the carrying value of an investment exceeds its fair value and the decline in value is determined to be other-than-temporary, an impairment charge is recorded and a new cost basis for the investment is established. Some of the factors considered in determining other-than-temporary impairment for equity securities include, but are not limited to, significant or prolonged declines in the fair value of the investments, the Company’s ability and intent to retain the investment for a period sufficient to allow the value to recover, and the financial condition of the investment. Some of the factors considered in determining other-than-temporary impairment for debt securities include, but are not limited to, the intent of management to sell the security, the likelihood that the Company will be required to sell the security before recovering its cost, and management’s expectation to recover the entire amortized cost basis of the security even if there is no intent to sell the security.

Fair Value of Financial Instruments

Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The fair value hierarchy requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The fair value hierarchy describes three levels of inputs that may be used by the Company to measure fair value:

Level 1 – Quoted prices in active markets for identical assets or liabilities without adjustment. The Company’s Level 1 assets primarily include investments in mutual funds sponsored by SEI and LSV that are quoted daily.

Level 2 – Observable inputs other than Level 1 prices, such as quoted prices for similar assets, quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 2 financial assets consist of Government National Mortgage Association (GNMA) mortgage-backed pass-through certificates, Federal Home Loan Bank (FHLB) and other U.S. government agency short-term notes and investment grade commercial paper. The Company's Level 2 financial assets, with the exception of the GNMA securities, were purchased as part of a cash management program requiring only short term, top-tier investment grade government and corporate securities. The GNMA mortgage-backed pass-through certificates were purchased for the sole purpose of satisfying specific regulatory requirements imposed on our wholly-owned limited purpose federal thrift subsidiary, SPTC. As a result, the Company's Level 2 financial assets are limited to only these types of fixed income securities.

Level 3 – Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Level 3 assets and liabilities include financial instruments whose value is determined using pricing models, or similar techniques, as well as instruments for which the determination of fair value requires significant judgment by management. The Company’s Level 3 financial assets primarily included structured investment vehicles (SIV) securities and any change in fair value for these securities is recognized in the current period.

The fair value of an asset or liability may include inputs from more than one level in the fair value hierarchy. The lowest level of significant inputs used to value the asset or liability determines which level the asset or liability is classified in its entirety.

See Note 5 for information on related disclosures regarding fair value measurements.

Capitalized Software

Costs incurred for the development of internal use software to be offered in a hosting arrangement is capitalized during the development stage of the software application. These costs include direct external and internal costs to design the software configuration and interfaces, coding, installation, and testing. Costs incurred during the preliminary and post-implementation stages of the software application are expensed as incurred. Costs associated with significant enhancements to a software application are capitalized while costs incurred to maintain existing software applications are expensed as incurred. The capitalization of software development costs requires considerable judgment by management with respect to certain external factors, including, but not limited to, technological and economic feasibility, and estimated economic life. Capitalized software development costs in 2012, 2011 and 2010 primarily relate to the further development of the Global Wealth Platform (GWP). The initial version of GWP was placed into service in July 2007. Further enhancements and upgrades will continue to occur through a series of releases. As of December 31, 2012, the net book value of GWP was $304,271, net of accumulated amortization of $119,939. Capitalized software development costs in-progress at December 31, 2012 associated with future releases to GWP were $2,795. The Company capitalized $31,004, $40,954, and $38,729 of software development costs during 2012, 2011, and 2010, respectively.

Amortization of capitalized software development costs begins when the product is ready for its intended use. Capitalized software development costs are amortized on a product-by-product basis using the straight-line method over the estimated economic life of the product or enhancement, which is primarily 3 to 15 years, with a weighted average remaining life of approximately 9.5 years. Amortization expense was $32,647, $26,153, and $23,053 in 2012, 2011, and 2010, respectively, and is included in Amortization expense on the accompanying Consolidated Statements of Operations. GWP has an estimated useful life of 15 years and a weighted average remaining life of 9.5 years. During 2012, the Company decided to discontinue the use of specific functionality within GWP and expensed the remaining net book value of $2,661 related to previously capitalized software development costs of the component. This cost is included in total amortization expense on the accompanying Consolidated Statements of Operations during 2012.

The Company evaluates the carrying value of capitalized software development costs when circumstances indicate the carrying value may not be recoverable. The review of capitalized software development costs for impairment requires significant assumptions about operating strategies, underlying technologies utilized, and external market factors. External market factors include, but are not limited to, expected levels of competition, barriers to entry by potential competitors, stability in the target market and governmental regulations. In 2012 and 2011, the Company determined that no events or change in circumstances had occurred that would indicate that capitalized software development costs were impaired. Therefore, no impairment charges were recognized by the Company for any of its capitalized software development costs in 2012 or 2011.

Income Taxes

The Company applies the asset and liability approach to account for income taxes whereby deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The components of the deferred tax assets and liabilities are individually classified as current and non-current based on their characteristics.

Foreign Currency Translation

The assets and liabilities and results of operations of the Company’s foreign subsidiaries are measured using the foreign subsidiary’s local currency as the functional currency. Assets and liabilities have been translated into U.S. dollars using the rates of exchange at the balance sheet dates. The results of operations have been translated into U.S. dollars at average exchange rates prevailing during the period. The resulting translation gain and loss adjustments are recorded as a separate component of comprehensive income.

Transaction gains and losses from exchange rate fluctuations are included in the results of operations in the periods in which they occur. There were no material gains or losses from exchange rate fluctuations in 2012, 2011 or 2010.

Earnings Per Common Share

Basic earnings per common share is computed by dividing net income attributable to SEI Investments common shareholders by the weighted average number of common shares outstanding during the period. Diluted earnings per common share is computed by dividing net income attributable to SEI Investments common shareholders by the combination of the weighted average number of common shares outstanding and the dilutive potential common shares, such as stock options, outstanding during the period. The calculations of basic and diluted earnings per share for 2012, 2011, and 2010 are:



	For the Year Ended December 31, 2012
	Net income attributable to SEI (Numerator)		Shares (Denominator)	Per-Share Amount
Basic earnings per common share	$	206,848	174,295	$	1.19
Dilutive effect of stock options	—		1,577
Diluted earnings per common share	$	206,848	175,872	$	1.18



	For the Year Ended December 31, 2011
	Net income attributable to SEI (Numerator)		Shares (Denominator)	Per-Share Amount
Basic earnings per common share	$	204,959	182,547	$	1.12
Dilutive effect of stock options	—		1,580
Diluted earnings per common share	$	204,959	184,127	$	1.11



	For the Year Ended December 31, 2010
	Net income attributable to SEI (Numerator)		Shares (Denominator)	Per-Share Amount
Basic earnings per common share	$	231,687	188,468	$	1.23
Dilutive effect of stock options	—		1,853
Diluted earnings per common share	$	231,687	190,321	$	1.22

Employee stock options to purchase approximately 13,202,000, 15,914,000, and 13,181,000 shares of common stock, with an average exercise price per share of $24.76, $23.07, and $23.79, were outstanding during 2012, 2011, and 2010, respectively, but not included in the computation of diluted earnings per common share because the option’s exercise price was greater than the average market price of the Company’s common stock and the effect on diluted earnings per common share would have been anti-dilutive (See Note 8).

Stock-Based Compensation

Stock-based compensation cost is measured at the grant date based on the fair value of the award and is recognized as expense over the requisite service period, which is the vesting period. The Company uses historical data to estimate pre-vesting forfeitures and record stock-based compensation expense only for those awards that are expected to vest. The amount of stock-based compensation expense that is recognized in a given period is dependent upon management’s estimate of when the vesting targets are expected to be achieved. If this estimate proves to be inaccurate, the remaining amount of stock-based compensation expense could be accelerated, spread out over a longer period, or reversed (See Note 8).

Reclassifications

Certain prior year amounts have been reclassified to conform to current year presentation.

- Definition

The entire disclosure for all significant accounting policies of the reporting entity.

+ References+ Details

Investment In Unconsolidated Affiliates

12 Months Ended

Dec. 31, 2012

Investment In Unconsolidated Affiliate [Abstract]

Investment In Unconsolidated Affiliates

Investment in Unconsolidated Affiliates

LSV Asset Management

The Company has an investment in the general partnership LSV Asset Management (LSV). LSV is a registered investment advisor that provides investment advisory services to institutions, including pension plans and investment companies. LSV is currently an investment sub-advisor for a limited number of SEI-sponsored mutual funds. The Company accounts for its interest in LSV using the equity method because of its less than 50 percent ownership. The Company’s interest in the net assets of LSV is reflected in Investment in unconsolidated affiliates on the accompanying Consolidated Balance Sheets and its interest in the earnings of LSV is reflected in Equity in earnings of unconsolidated affiliates on the accompanying Consolidated Statements of Operations.

In March 2009, certain partners (the Contributing partners) of LSV, including the Company, designated a portion of their partnership interest for the purpose of providing an interest in the partnership to a select group of key employees. Until such time an interest in the partnership is issued to a key employee, all profits, losses, distributions and other rights and obligations relating to such unissued interests remains with the Contributing partners. Each issuance must be authorized by unanimous vote of all Contributing partners. In April 2012, the Contributing partners agreed to provide certain key employees an interest in LSV, thereby reducing the Company’s interest in LSV from approximately 41.2 percent to approximately 39.8 percent.

At December 31, 2012, the Company’s total investment in LSV was $68,716. The investment in LSV exceeded the underlying equity in the net assets of LSV by $3,280, of which $3,062 is considered goodwill embedded in the investment. The Company’s proportionate share in the earnings of LSV was $99,989, $105,818 and $99,457 in 2012, 2011 and 2010, respectively. The Company receives partnership distributions from LSV on a quarterly basis. The Company received partnership distribution payments from LSV for $92,227, $109,273 and $93,302 in 2012, 2011 and 2010, respectively. The partnership distribution payment of $21,242 received in January 2010 is reflected in LSV and LSV Employee Group cash balances, net on the accompanying Consolidated Statement of Cash Flows.

These tables contain condensed financial information of LSV:



Condensed Statement of Operations Year ended December 31,	2012		2011		2010
Revenues	$	296,261	$	296,397	$	273,381
Net income	$	250,165	$	257,519	$	239,981



Condensed Balance Sheets December 31,	2012		2011
Current assets	$	145,367	$	136,601
Non-current assets	3,120		3,880
Total assets	$	148,487	$	140,481

Current liabilities	$	17,869	$	13,933
Partners’ capital	130,618		126,548
Total liabilities and partners’ capital	$	148,487	$	140,481

Guaranty Agreement with LSV Employee Group

LSV Employee Group is owned by several current employees of LSV and was formed for the sole purpose of owning a partnership interest in LSV. The Company does not own any interest in LSV Employee Group. In 2006, LSV Employee Group obtained financing from Bank of America, N.A. (Bank of America) and certain other lenders in the form of a term loan in the amount of $82,800 pursuant to the terms of a Credit Agreement. The Company agreed to provide a Guaranty Agreement to the lenders of all obligations of LSV Employee Group under the Credit Agreement. The Company’s direct interest in LSV was unchanged as a result of this transaction.

In January 2011, LSV Employee Group and Bank of America agreed to amend the Credit Agreement and extend the maturity date of the loan from January 2011 to July 2012. The Company’s obligations under the Guaranty Agreement remained in full force and effect with respect to the amended Credit Agreement. LSV Employee Group made the final principal payment of the term loan in October 2011 and the Company has no further obligation regarding the Guaranty Agreement.

Guaranty Agreement with LSV Employee Group II

In April 2011, a group of existing employees of LSV formed a new limited liability company, LSV Employee Group II, and agreed to purchase a partnership interest of an existing LSV employee for $4,300 of which $3,655 was financed through a new term loan with Bank of America. The Company provided an unsecured guaranty to the lenders of all the obligations of LSV Employee Group II. The lenders will have the right to seek payment from the Company in the event of a default by LSV Employee Group II. The term loan has a four year term and will be repaid from the quarterly distributions of LSV. LSV Employee Group II made principal payments of $1,031 and $458 during 2012 and 2011, respectively. As of December 31, 2012, the remaining unpaid principal balance of the term loan was $2,166. This amount is not reflected, nor is it required to be reflected, in the Company’s Consolidated Balance Sheet at December 31, 2012.

The Company’s direct interest in LSV was unchanged as a result of this transaction. The Company has determined that LSV Employee Group II is a VIE; however, the Company is not considered the primary beneficiary because it does not have the power to direct the activities that most significantly impact the economic performance of LSV Employee Group II either directly or through any financial responsibility from the guaranty.

As of January 31, 2013, the remaining unpaid principal balance of the term loan was $1,923. The Company, in its capacity as guarantor, currently has no obligation of payment relating to the term loan of LSV Employee Group II and, furthermore, fully expects that LSV Employee Group II will meet all of their future obligations regarding the term loan.

Guaranty Agreement with LSV Employee Group III

In October 2012, a group of existing employees of LSV formed a new limited liability company called LSV Employee Group III and agreed to purchase a portion of the partnership interest of three existing LSV employees for $77,700, of which $69,930 was financed through two syndicated term loan facilities contained in a credit agreement with The PrivateBank and Trust Company. LSV Employee Group III owns the purchased partnership interest. The Company provided an unsecured guaranty for $45,000 of the obligations of LSV Employee Group III to the lenders through a guaranty agreement. In addition, LSV agreed to provide an unsecured guaranty for the remaining $24,930 of the obligations of LSV Employee Group III to the lenders through a separate guaranty agreement. The loan facility guaranteed by LSV has a three year term and will be repaid from the quarterly distributions of LSV. LSV Employee Group III made no principal payments on the term loans during 2012.

With regard to the loan facility guaranteed by the Company, the lenders will have the right to seek payment from the Company in the event of a default by LSV Employee Group III. The loan facility has a five year term and will be repaid from the quarterly distributions of LSV. No principal payments will be made by LSV Employee Group III on the loan facility guaranteed by the Company until the separate loan facility guaranteed by LSV is fully repaid.

The Company’s direct interest in LSV was unchanged as a result of this transaction. The Company has determined that LSV Employee Group III is a VIE; however, the Company is not considered the primary beneficiary because it does not have the power to direct the activities that most significantly impact the economic performance of LSV Employee Group III either directly or through any financial responsibility from the guaranty.

In January 2013, LSV Employee Group III made a principal payment of $2,367 related to the term loan guaranteed by LSV. As of January 31, 2013, the remaining unpaid principal balances of the term loans guaranteed by LSV and the Company were $22,563 and $45,000, respectively. The Company, in its capacity as guarantor, currently has no obligation of payment relating to the term loan of LSV Employee Group III and, furthermore, fully expects that LSV Employee Group III will meet all of their future obligations regarding the term loan.

Investment in Gao Fu Limited

The Company has an investment in Gao Fu Limited (Gao Fu), a wealth services firm based in Shanghai in the Republic of China. The Company accounts for its interest in Gao Fu using the equity method because of its less than 50 percent ownership. The Company’s interest in the net assets of Gao Fu is reflected in Investment in unconsolidated affiliates on the accompanying Consolidated Balance Sheets and its interest in the earnings or losses of Gao Fu is reflected in Equity in earnings of unconsolidated affiliates on the accompanying Consolidated Statements of Operations.

At December 31, 2012, the Company's total investment in Gao Fu was $8,682. The majority of the Company's investment exceeded the underlying equity in the net assets of Gao Fu and is considered goodwill embedded in the investment. The Company's proportionate share in the losses of Gao Fu was $1,318 in 2012.

- Definition

The entire disclosure for equity method investments and joint ventures. Equity method investments are investments that give the investor the ability to exercise significant influence over the operating and financial policies of an investee. Joint ventures are entities owned and operated by a small group of businesses as a separate and specific business or project for the mutual benefit of the members of the group.

+ References+ Details

Variable Interest Entities - Investment Products	12 Months Ended
Variable Interest Entities - Investment Products	Dec. 31, 2012
Variable Interest Entities - Investment Products [Abstract]
Variable Interest Entities - Investment Products	Variable Interest Entities – Investment Products The Company has created numerous investment products for its clients in various types of legal entity structures. The Company serves as the Manager, Administrator and Distributor for these investment products and may also serve as the Trustee for some of the investment products. Clients are the equity investors and participate in proportion to their ownership percentage in the net income or loss and net capital gains or losses of the products, and, on liquidation, will participate in proportion to their ownership percentage in the remaining net assets of the products after satisfaction of outstanding liabilities. An entity that lacks decision-making rights is a VIE. In some circumstances, the Manager or Trustee of the Company’s investment products controls the governing decisions about the investment activities with respect to the ongoing operations of the investment products without the equity investors possessing the right to remove the Manager or Trustee. Therefore, the equity investors, as a group, do not have the ability to make decisions that have an impact on the ongoing activities of such investment products. Consequently, some of the Company’s investment products have been determined to be VIEs at inception. The VIEs are marketed with investment objectives to generate positive returns; however, the nature of such investments exposes the investors to the risk that the value of the VIEs may increase or decrease. The purpose and design of the VIEs are to achieve the investment objective by implementing strategies which are designed to minimize potential losses; however, there is no assurance given that these strategies will be successful. The Company does not have a significant equity investment in any of the VIEs and does not have an obligation to enter into any guarantee agreements with the VIEs. The fees paid to the decision maker of a VIE are considered to be variable interests if the decision maker is not subject to substantive kick-out rights. The fees paid to the Company represent a variable interest when the decision maker is not subject to substantive kick-out rights. The Company is not the primary beneficiary of the VIEs because the expected fees and the expected return on any investment into the VIE by the Company relative to the expected returns of the VIE to the equity investor holders does not approach 50 percent of the expected losses or gains of the VIEs. Therefore, the Company is not required to consolidate any investment products that are VIEs into its financial statements. The Company’s variable interest in the VIEs, which consists of management fees and in some situations, seed capital, would not be considered a significant variable interest. The risks to the Company associated with its involvement with any of the investment products that are VIEs are limited to the cash flows received from the revenue generated for asset management, administration and distribution services and any equity investments in the VIEs. Both of these items are immaterial. The Company has no other financial obligation to the VIEs. Amounts relating to fees received from the VIEs included in Receivables and amounts relating to equity investments in the VIEs included in Investments Available for Sale on the Company’s Consolidated Balance Sheets are immaterial to the total current assets of the Company.

Composition Of Certain Financial Statement Captions

12 Months Ended

Dec. 31, 2012

Items Included in Consolidated Statement of Financial Condition [Abstract]

Composition Of Certain Financial Statement Captions

Composition of Certain Financial Statement Captions

Receivables

Receivables on the accompanying Consolidated Balance Sheets consist of:



	2012			2011
Trade receivables	$	46,650		$	37,822
Fees earned, not billed	116,019			92,916
Other receivables	9,870			12,295
	172,539			143,033
Less: Allowance for doubtful accounts	(805		)	(924		)
Receivables, net	$	171,734		$	142,109

Fees earned, not billed represents receivables earned but unbilled and results from timing differences between services provided and contractual billing schedules. These billing schedules generally provide for fees to be billed on a quarterly basis. In addition, certain fees earned from investment operations services are determined from security valuations which delay billings to clients.

Receivables from regulated investment companies on the accompanying Consolidated Balance Sheets primarily represent fees receivable for distribution, investment advisory, and administration services to various regulated investment companies sponsored by SEI (See Note 14).

Property and Equipment

Property and Equipment on the accompanying Consolidated Balance Sheets consists of:



	2012			2011
Buildings	$	137,751		$	136,949
Equipment	66,167			64,256
Land	9,929			9,929
Purchased software	91,468			77,971
Furniture and fixtures	18,535			17,999
Leasehold improvements	5,037			4,558
Construction in progress	112			339
	328,999			312,001
Less: Accumulated depreciation	(201,418		)	(182,453		)
Property and Equipment, net	$	127,581		$	129,548

Depreciation expense related to property and equipment for 2012, 2011, and 2010 was $22,586, $21,471, and $21,902, respectively.

Other Assets

Other assets consist of long-term prepaid expenses, deposits, other investments at cost and various other assets. Amortization expense for certain other assets for 2012, 2011, and 2010 was $611, $1,135 and $995, respectively.

The Company recognized gains of $3,072 in 2010 due to the sale of its entire ownership interest in a small, private company that was involved in a merger. The Company’s investment in the firm had been accounted for under the cost basis. The gain is reflected in Net gain on investments on the accompanying Consolidated Statements of Operations.

Accrued Liabilities

Accrued Liabilities on the accompanying Consolidated Balance Sheets consist of:



	2012		2011
Accrued employee compensation	$	63,996	$	48,112
Accrued employee benefits and other personnel	7,299		5,408
Accrued consulting, outsourcing and professional fees	16,676		17,477
Accrued brokerage fees	5,733		8,665
Accrued sub-advisory, distribution and other asset management fees	17,548		17,091
Accrued dividend payable	—		26,518
Other accrued liabilities	27,053		23,773
Accrued liabilities	$	138,305	$	147,044

Fair Value Measurements

12 Months Ended

Dec. 31, 2012

Fair Value Disclosures [Abstract]

Fair Value Measurements

The fair value of the Company’s financial assets and liabilities is determined in accordance with the fair value hierarchy. The fair value of the Company’s Level 1 financial assets consist mainly of investments in equities and mutual funds that are quoted daily. Level 2 financial assets consist of Government National Mortgage Association (GNMA) mortgage-backed pass-through certificates, Federal Home Loan Bank (FHLB) and other U.S. government agency short-term notes and investment grade commercial paper. The Company's Level 3 financial assets primarily consisted of senior note obligations issued by SIVs. In November 2012, the Company sold its remaining SIV security, the Gryphon senior note, and recognized a gain of $5,322 from the sale. As of December 31, 2012, the Company no longer owns any SIV securities.

The Company had no Level 3 financial liabilities at December 31, 2012 or 2011. There were no transfers of financial assets between levels within the fair value hierarchy during 2012 or 2011.

Valuation of GNMA, Other U.S. Government Agency Securities and Investment Grade Commercial Paper

All of the Company's investments in GNMA, other U.S. government agency securities and investment grade commercial paper are held in accounts at well-established financial institutions. The Company's selection of a financial institution for the purpose of purchasing securities considered a number of various factors including, but not limited to, securities pricing policies and procedures utilized by that financial institution. Each financial institution utilizes the services of independent pricing vendors. These vendors utilize evaluated and industry accepted pricing models that vary by asset class and incorporate available trade, bid and other market information to determine the fair value of the securities. The market inputs, listed in approximate order of priority, include: benchmark yields, reported trade, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers and reference data. The Company evaluated the information regarding the pricing methodologies and processes utilized by the independent pricing vendors during the selection process of the financial institution. The Company analyzed this information for the purpose of classifying the securities into the appropriate level within the fair value hierarchy and to ensure that each pricing model for each asset class provided the fair value of those specific securities in accordance with generally accepted accounting principles. The Company continually monitors the price of each security for any unanticipated deviations from the previously quoted price or deviations from anticipated changes in a security's price based upon an assessment of market factors and other factors relative to a specific issue expected to affect a security's price. In the event a security price changed in excess of management's pre-established tolerance levels, additional analysis is conducted which may include the comparison of the security's price as determined by other independent pricing vendors. The Company's investments in GNMA, other U.S. government agency securities and investment grade commercial paper have been recorded at the prices provided by the independent pricing vendor without adjustment.

Valuation of SIV Securities

The underlying collateral of the SIV securities is mainly comprised of asset-backed securities and collateralized debt obligations. The Company utilizes the services of an independent firm that specializes in securities valuations to assist in determining the fair value of the SIV security owned. The Company's selection of the independent valuation firm was based upon a review of their modeling techniques and assumptions utilized within their models for each asset class rather than at a specific security level. Management also considered the reputation of the valuation firm and their expertise associated with SIV securities and other types of illiquid securities. Finally, management confirmed prior to selection of the valuation firm that the estimated fair value conformed to generally accepted accounting principles. On a quarterly basis, management evaluates a detailed description of the modeling techniques and types of inputs used for each major asset class which is reviewed to ensure consistent application since the initial selection of the valuation firm. Additionally, management receives the estimated fair value of each individual security that comprises the underlying collateral which is compared to the previous quarter's estimated fair value to identify and discuss significant fluctuations with the valuation firm.

The model used by the independent valuation firm to determine the fair value of the SIV security attempts to value the underlying collateral of the SIV security through the use of industry accepted and proprietary valuation techniques and models. This approach combines advanced analytics with real-time market information that incorporate structural and fundamental analysis, collateral characteristics and recent market developments. Each security that makes up the underlying collateral is specifically identified by its CUSIP or ISIN number and is analyzed by using observable collateral characteristics and credit statistics in order to project future performance and expected cash flows for each individual security. The projected cash flows incorporate assumptions and expectations based upon the foregoing analysis of the collateral characteristics such as, but not limited to, default probabilities, recovery rates, prepayment speeds and loss severities. Expected future cash flows are discounted at an appropriate yield derived from the individual security, structural and collateral characteristics, trading levels and other available market data. Different modeling techniques and associated inputs and assumptions may be used to project future cash flows for each security depending upon the asset classification of that individual security (i.e. residential mortgage-backed security, commercial mortgage-backed security, collateralized debt obligations, etc.). The aggregate value of the discounted cash flows of the underlying collateral is compared to the total remaining par value of the collateral to determine the expected recovery price, or fair value, of the remaining note obligations. Other factors may be considered that are specific to the SIV security that may affect the fair value of the SIV security.

Management also considered, when available, price quotes from brokers and dealers. If a price quote was available, management compared this number to the fair value derived from the valuation model of the independent firm giving consideration to other market factors and risk premiums. In the event a market transaction did exist for a SIV security, management evaluated the publicly available information surrounding the transaction in order to assess if the price used represented the fair value for the SIV security. Given the lack of any significant trading activity for the SIV security owned by the Company, management concluded that market prices did not represent the security's implied fair value.

The fair value of certain financial assets and liabilities of the Company was determined using the following inputs:



			December 31, 2012
			Fair Value Measurements at Reporting Date Using
	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets
Equity available-for-sale securities	$	15,926	$	15,926	$	—	$	—
Fixed-income available-for-sale securities	59,943		—		59,943		—
Fixed income securities owned	20,088		—		20,088		—
Trading securities	5,909		4,706		—		1,203
	$	101,866	$	20,632	$	80,031	$	1,203



			December 31, 2011
			Fair Value Measurements at Reporting Date Using
	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets
Equity available-for-sale securities	$	8,010	$	8,010	$	—	$	—
Fixed-income available-for-sale securities	74,998		—		74,998		—
Fixed income securities owned	20,949		—		20,949		—
Trading securities	56,325		3,702		—		52,623
	$	160,282	$	11,712	$	95,947	$	52,623

The table below presents a reconciliation for all assets and liabilities of the Company measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the period from January 1, 2011 to December 31, 2012:



	Trading Securities
Balance, January 1, 2011	$	100,645
Purchases	1,215
Issuances	—
Principal prepayments and settlements	(17,921		)
Sales	(34,706		)
Total gains or (losses) (realized/unrealized):
Included in earnings	3,390
Included in other comprehensive income	—
Transfers in and out of Level 3	—
Balance, December 31, 2011	$	52,623
Purchases	13
Issuances	—
Principal prepayments and settlements	(10,728		)
Sales	(53,920		)
Total gains or (losses) (realized/unrealized):
Included in earnings	13,215
Included in other comprehensive income	—
Transfers in and out of Level 3	—
Balance, December 31, 2012	$	1,203

- Definition

The entire disclosure of the fair value measurement of assets and liabilities, which includes financial instruments measured at fair value that are classified in shareholders' equity, which may be measured on a recurring or nonrecurring basis.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 33

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 107

-Paragraph 10

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19279-110258

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19190-110258

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 6

-Footnote 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Marketable Securities

12 Months Ended

Dec. 31, 2012

Marketable Securities [Abstract]

Marketable Securities

Investments Available For Sale

Investments available for sale classified as non-current assets consist of:



	At December 31, 2012
	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Fair Value
SEI-sponsored mutual funds	$	12,953	$	376	$	(13	)	$	13,316
Equities and other mutual funds	2,610		—		—			2,610
Debt securities	55,923		4,020		—			59,943
	$	71,486	$	4,396	$	(13	)	$	75,869



	At December 31, 2011
	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Fair Value
SEI-sponsored mutual funds	$	8,243	$	48	$	(360	)	$	7,931
Other mutual funds	69		10		—			79
Debt securities	70,604		4,394		—			74,998
	$	78,916	$	4,452	$	(360	)	$	83,008

Net unrealized holding gains at December 31, 2012 and 2011 were $2,829 (net of income tax expense of $1,554) and $2,574 (net of income tax expense of $1,518), respectively. These net unrealized gains are reported as a separate component of Accumulated other comprehensive income on the accompanying Consolidated Balance Sheets.

There were no material gross realized gains or losses from available-for-sale securities during 2012, 2011 and 2010. Gains and losses from available-for-sale securities are reflected in Net gain from investments on the accompanying Consolidated Statements of Operations.

The Company’s debt securities are issued by the Government National Mortgage Association and are backed by the full faith and credit of the U.S. government. These securities were purchased to satisfy applicable regulatory requirements of SPTC and have maturity dates which range from 2020 to 2041.

Trading Securities

Trading securities of the Company consist of:



	At December 31, 2012
	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Fair Value
LSV-sponsored mutual funds	$	2,049	$	2,657	$	—		$	4,706
Other investments	1,228		—		(25		)	1,203
	$	3,277	$	2,657	$	(25	)	$	5,909



	At December 31, 2011
	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Fair Value
SIV securities	$	146,363	$	—	$	(94,955	)	$	51,408
LSV-sponsored mutual funds	2,049		1,653		—			3,702
Other investments	1,215		—		—			1,215
	$	149,627	$	1,653	$	(94,955	)	$	56,325

The Company records all of its trading securities on the accompanying Consolidated Balance Sheets at fair value. Unrealized gains and losses from the change in fair value of these securities are recognized in Net gain from investments on the accompanying Consolidated Statements of Operations.

During 2012, 2011 and 2010, the Company recognized net gains from SIV securities of $13,240, $3,390 and $44,247 respectively. Of the net gains recognized during 2012, gains of $6,776 resulted from cash payments received from the SIV securities and $1,142 was from a net increase in fair value. In November 2012, the Company sold the senior notes issued by Gryphon and recognized a gain of $5,322 from the sale. The Company no longer owns any SIV securities.

During 2011, the Company recognized gains from SIV securities of $3,390, of which $10,614 resulted from cash payments received from the SIV securities offset by losses of $7,224 which resulted from a decrease in fair value at December 31, 2011. In January 2011, the Company sold the senior note issued by Stanfield Victoria. There was no gain or loss recognized by the Company from the sale of the note as the fair value of the Stanfield Victoria note at December 31, 2010 was not different than the sale price received.

During 2010, the Company recognized gains from SIV securities of $44,247, of which $27,510 resulted from cash payments received from the SIV securities and $16,460 was from a net increase in fair value at December 31, 2010. The net gains from the SIV securities are reflected in Net gain from investments on the accompanying Consolidated Statements of Operations.

The Company has an investment related to the startup of mutual funds sponsored by LSV. These are U.S. dollar denominated funds that invests primarily in securities of Canadian, Australian and Japanese companies as well as various other global securities. The underlying securities held by the funds are translated into U.S. dollars within the funds. Net gains from the change in fair value of the funds were $1,004 during 2012. There were no material net gains or losses from the change in fair value of the funds during 2011.

Securities Owned

The Company’s broker-dealer subsidiary, SIDCO, has investments in U.S. government agency and commercial paper securities with maturity dates less than one year. These investments are reflected as Securities owned on the accompanying Consolidated Balance Sheets. Due to specialized accounting practices applicable to investments by broker-dealers, the securities are reported at fair value and changes in fair value are recorded in current period earnings. The securities had a fair value of $20,088 and $20,949 at December 31, 2012 and 2011, respectively. There were no material net gains or losses from the change in fair value of the securities during 2012 and 2011.

- Definition

Tabular disclosure of marketable securities. This may consist of investments in certain debt and equity securities, short-term investments and other assets.

+ References+ Details

Lines Of Credit	12 Months Ended
Lines Of Credit	Dec. 31, 2012
Line of Credit Facility [Abstract]
Lines Of Credit	Lines of Credit On February 2, 2012 (the Closing Date), the Company entered into a new five-year $300,000 Credit Agreement (the Credit Facility) with Wells Fargo Bank, National Association, and a syndicate of other lenders. The Credit Facility became available on the Closing Date and is scheduled to expire in February 2017, at which time any aggregate principal amount of loans outstanding becomes payable in full. Any borrowings made under the Credit Facility will accrue interest at 1.250 percent above the London Interbank Offer Rate (LIBOR). There is also a commitment fee equal to 0.150 percent per annum on the daily unused portion of the facility. The aggregate amount of the Credit Facility may be increased by an additional $100,000 under certain conditions set forth in the agreement. The Credit Facility contains covenants that restrict the ability of the Company to engage in mergers, consolidations, asset sales, investments, transactions with affiliates, or to incur liens, as defined in the agreement. In the event of a default under the Credit Facility, the Company would also be restricted from paying dividends on, or repurchasing, its common stock without the approval of the lenders. None of the covenants of the Credit Facility negatively affect the Company’s liquidity or capital resources. Both the interest rate and commitment fee prices may increase if the Company’s leverage ratio reaches certain levels. Upon the occurrence of certain financial or economic events, significant corporate events, or certain other events of default constituting an event of default under the Credit Facility, all loans outstanding may be declared immediately due and payable and all commitments under the Credit Facility may be terminated. The Company had no borrowings through the Credit Facility at December 31, 2012. The Company was in compliance with all covenants of the Credit Facility at December 31, 2012. Prior to entering into the Credit Facility, the Company maintained a $300,000 revolving line of credit through a Credit Agreement, as amended, with JPMorgan Chase Bank, N.A. and a syndicate of other lenders (the 2007 Credit Facility). Outstanding borrowings under the 2007 Credit Facility accrued interest at 0.450 percent above LIBOR. There was also a commitment fee equal to 0.09 percent per annum on the daily unused portion of the facility charged to the Company. The 2007 Credit Facility, as amended, contained covenants that restricted the ability of the Company to engage in mergers, consolidations, asset sales, investments, transactions with affiliates, or to incur liens, as defined in the agreement. The Company had no borrowings through the 2007 Credit Facility at December 31, 2011. None of the covenants of the 2007 Credit Facility negatively affected the Company’s liquidity or capital resources. The Company made principal payments of $95,000 and $138,000 during 2011 and 2010 to repay the remaining outstanding balance of the 2007 Credit Facility. The Company had no borrowings from the Credit Facility during 2012. The average rates applied to the 2007 Credit Facility during 2011 and 2010 were 0.68 percent and 0.77 percent, respectively. The Company incurred $471, $585 and $1,478 in interest charges and commitment fees relating to all lines of credit during 2012, 2011 and 2010, respectively, which are reflected in Interest expense on the accompanying Consolidated Statements of Operations. The Company’s Canadian subsidiary has a credit facility agreement (the Canadian Credit Facility) for the purpose of facilitating the settlement of mutual fund transactions. The Canadian Credit Facility has no stated expiration date. The amount of the facility is generally limited to $2,000 Canadian dollars or the equivalent amount in U.S. dollars. The Canadian Credit Facility does not contain any covenants which restrict the liquidity or capital resources of the Company. The Company had no borrowings under the Canadian Credit Facility and was in compliance with all covenants during 2012.

Shareholders' Equity

12 Months Ended

Dec. 31, 2012

Stockholders' Equity Note [Abstract]

Shareholders' Equity

Shareholders’ Equity

Stock-Based Compensation

The Company currently has one active equity compensation plan, the 2007 Equity Compensation Plan (the 2007 Plan), which provides for the grant of incentive stock options, non-qualified stock options and stock appreciation rights with respect to up to 20 million shares of common stock of the Company, subject to adjustment for stock splits, reclassifications, mergers and other events. Permitted grantees under the 2007 Plan include employees, non-employee directors and consultants who perform services for the Company. The plan is administered by the Compensation Committee of the Board of Directors of the Company. The Company has only granted non-qualified stock options under the plan.

The Company discontinued any further grants under the Company’s 1998 Equity Compensation Plan (the 1998 Plan) as a result of the approval of the 2007 Plan. There are no options available for grant from this plan. Grants made from the 1998 Plan continue in effect under the terms of the grant.

All outstanding stock options have performance-based vesting provisions that tie the vesting of stock options to the Company’s financial performance. The Company’s stock options vest at a rate of 50 percent when a specified diluted earnings per share target is achieved, and the remaining 50 percent when a second, higher specified diluted earnings per share target is achieved. Stock options granted prior to 2006 fully vest after 7 years from the date of grant. Beginning in 2006, the 7 year vesting trigger was eliminated and, as a result, options do not vest due to the passage of time but solely as a result of achievement of the financial vesting targets. Earnings per share targets are calculated exclusive of stock-based compensation expense, net of tax. The diluted earnings per share targets are established at time of grant and are measured annually on December 31. The amount of stock-based compensation expense is based upon management’s estimate of when the earnings per share targets may be achieved. If management’s estimate of the attainment of the earnings per share targets proves to be inaccurate, the remaining amount of stock-based compensation expense could be accelerated, spread out over a longer period, or reversed. This may cause volatility in the recognition of stock-based compensation expense in future periods and could materially affect the Company’s net income and net income per share.

The Company uses the Black-Scholes option pricing model to determine the fair value of stock options. The determination of the fair value of stock options on the date of grant using an option-pricing model is affected by the price of the Company’s common stock as well as other variables. These variables include expected stock price volatility over the term of the awards, actual and projected employee stock exercise behaviors, risk-free interest rate and expected dividends. The Company primarily uses historical data to estimate the variables used in the option-pricing model except expected volatility. The Company uses a combination of historical and implied volatility. The Company estimates forfeitures at the time of grant and may revise those estimates in subsequent periods if actual forfeitures differ from those estimates. The Company uses historical data to estimate pre-vesting forfeitures and record stock-based compensation expense only for those awards that are expected to vest. Stock-based compensation is amortized over the requisite service periods of the awards, which are generally the vesting periods.

The weighted average fair value of the Company’s stock options granted during 2012, 2011 and 2010 were $6.73, $5.70 and $9.65, respectively, using the following assumptions:



	2012		2011		2010
Expected term (in years)	6.75		7.65		7.45
Expected volatility	34.90	%	40.43	%	36.35	%
Expected dividend yield	1.46	%	1.90	%	0.84	%
Risk-free interest rate	1.03	%	1.66	%	3.01	%

The Company recognized stock-based compensation expense in its Consolidated Financial Statements in 2012, 2011 and 2010 as follows:



	2012			2011			2010
Stock-based compensation expense	$	15,736		$	14,112		$	26,783
Less: Deferred tax benefit	(5,650		)	(5,332		)	(10,068		)
Stock-based compensation expense, net of tax	$	10,086		$	8,780		$	16,715

During 2010, the Company revised its estimates of when some vesting targets are expected to be achieved. These changes in management’s estimates resulted in an increase of $11,663 in stock-based compensation expense in 2010. Additionally, during the three months ended September 30, 2010, the Company reversed $6,375 of previously-recognized stock-based compensation costs pertaining to option grants which management does not expect to vest. Management does not expect to recognize any compensation cost associated with these option grants. As of December 31, 2010, these option grants have an unrecognized compensation cost of $27,460.

As of December 31, 2012, there was approximately $50,264 of unrecognized compensation cost remaining, adjusted for estimated forfeitures, related to unvested employee stock options that the Company expects will vest and is being amortized.

This table presents certain information relating to the Company’s stock option plans for 2012, 2011, and 2010:



	Number of Shares		Weighted Avg. Price
Balance as of December 31, 2009	28,964,000		$	20.09
Granted	2,883,000		23.84
Exercised	(1,633,000	)	16.04
Expired or canceled	(2,333,000	)	23.68
Balance as of December 31, 2010	27,881,000		$	20.42
Granted	2,534,000		15.77
Exercised	(1,364,000	)	16.37
Expired or canceled	(2,008,000	)	22.07
Balance as of December 31, 2011	27,043,000		$	20.06
Granted	2,470,000		22.40
Exercised	(3,136,000	)	15.19
Expired or canceled	(767,000	)	22.61
Balance as of December 31, 2012	25,610,000		$	20.81

Exercisable as of December 31, 2012	9,760,000		$	18.11
Available for future grant as of December 31, 2012	2,569,000

As of December 31, 2011 and 2010, there were 11,680,000 and 14,247,000 shares exercisable, respectively. The expiration dates for options outstanding at December 31, 2012 range from December 16, 2013 to December 11, 2022 with a weighted average remaining contractual life of 5.9 years.

Upon exercise of stock options, the Company will issue new shares of its common shares. The Company does not hold any shares in treasury. The total intrinsic value of options exercised during 2012 and 2011 was $19,565 and $8,642, respectively. The total options exercisable as of December 31, 2012 had an intrinsic value of $51,087. The total options outstanding as of December 31, 2012 had an intrinsic value of $64,823. The total intrinsic value for options outstanding and options exercisable is calculated as the difference between the market value of the Company’s common stock as of December 31, 2012 and the exercise price of the shares. The market value of the Company’s common stock as of December 31, 2012 was $23.34 as reported by the Nasdaq Stock Market, LLC.

This table summarizes information relating to all options outstanding and exercisable at December 31, 2012:



				Options Outstanding at December 31, 2012				Options Exercisable at December 31, 2012
Range of Exercise Prices (Per Share)				Number of Shares	Weighted Average Exercise Price (Per Share)		Weighted Average Remaining Contractual Life (Years)	Number of Shares	Weighted Average Exercise Price (Per Share)		Weighted Average Remaining Contractual Life (Years)
$	14.62	-	15.52	5,065,000	$	14.69	4.36	3,153,000	$	14.73	3.36
15.77		-	17.65	5,999,000	16.87		7.81	1,647,000	17.63		6.92
18.00		-	21.55	4,981,000	20.37		2.57	4,945,000	20.39		2.51
22.45		-	23.86	5,143,000	23.19		8.94	—	—		—
27.03		-	32.49	4,422,000	30.88		4.46	15,000	27.03		4.00
				25,610,000				9,760,000

Employee Stock Purchase Plan

The Company has an employee stock purchase plan that provides for offerings of common stock to eligible employees at a price equal to 85 percent of the fair market value of the stock at the end of the stock purchase period, as defined. The Company has reserved 15,600,000 shares for issuance under this plan. At December 31, 2012, 11,580,000 cumulative shares have been issued. There were no material costs incurred by the Company related to the employee stock purchase plan in 2012, 2011 and 2010.

Common Stock Buyback

The Board of Directors, under multiple authorizations, has authorized the purchase of the Company’s common stock on the open market or through private transactions. As of December 31, 2012, the Company had approximately $91,012 of authorization remaining for the purchase of common stock. The following table provides the total number of shares repurchased and the related total costs in 2012, 2011 and 2010:



Year	Total Number of Shares Repurchased	Total Cost
2012	7,528,000	$	155,264
2011	11,109,000	211,165
2010	5,814,000	120,982

The Company immediately retires its common stock when purchased. Upon retirement, the Company reduces Capital in excess of par value for the average capital per share outstanding and the remainder is charged against Retained earnings. If the Company reduces its Retained earnings to zero, any subsequent purchases of common stock will be charged entirely to Capital in excess of par value.

Rights Agreement

In December 2008, the Company’s Board of Directors declared a dividend distribution pursuant to a Rights Agreement (the Rights Agreement) which became effective on January 6, 2009. The purpose of the Rights Agreement is to deter coercive or unfair takeover tactics and to prevent a person or group (an Acquiring Person) from acquiring control of the Company without offering a fair price to all shareholders. Under the Rights Agreement, all common shareholders receive one Right for each common share outstanding. Each Right entitles the registered holder to purchase from the Company a unit consisting of one twenty-thousandths of a share of Series A Junior Participating Preferred Shares, $0.05 par value per share, or a combination of securities and assets of equivalent value, at a purchase price of $150.00 per unit, subject to adjustment. The Rights will become exercisable and trade separately from the common stock ten days following a public announcement that an Acquiring Person has beneficial ownership of more than 20 percent of the outstanding common stock of the Company or the commencement of a tender or exchange offer that would result in an Acquiring Person owning 20 percent or more of the outstanding common stock of the Company. Upon exercise, holders, other than an Acquiring Person, will have the right to purchase the common stock of the Company equal to twice the value of the exercise price of the Rights. In lieu of requiring payment of the purchase price upon exercise of the Rights following certain events, the Company may permit the holders simply to surrender the Rights, in which event they will be entitled to receive common shares and other property, as the case may be, with a value of 50 percent of what could be purchased by payment of the full purchase price. The Rights, which do not have voting rights, will expire on January 6, 2019, and may be redeemed by the Company any time until ten days following the announcement of an Acquiring Person at a price of $0.01 per Right.

Cash Dividends

On May 23, 2012, the Board of Directors declared a cash dividend of $0.15 per share on the Company’s common stock, which was paid on June 26, 2012, to shareholders of record on June 18, 2012. On December 11, 2012, the Board of Directors declared a cash dividend of $0.16 per share on the Company’s common stock, which was paid on December 28, 2012, to shareholders of record on December 21, 2012. Also on December 11, 2012, the Board of Directors declared a special cash dividend of $0.32 per share in the Company’s common stock, which was paid on December 28, 2012 to shareholders of record on December 21, 2012.

The cash dividends declared in 2012, 2011, and 2010 were $108,817, $48,558, and $37,513 respectively. The Board of Directors has indicated its intention to declare future cash dividends on a semiannual basis.

Noncontrolling Interest

The following table provides a reconciliation of Noncontrolling interest on the Consolidated Statements of Changes in Equity:



Year Ended December 31,	2012		2011			2010
Noncontrolling interest
Beginning balance	$	16,143	$	15,155		$	121,895
Net income attributable to noncontrolling interest	1,186		1,691			1,633
Foreign currency translation adjustments	1,820		(703		)	685
Deconsolidation of LSV	—		—			(65,522		)
Deconsolidation of LSV Employee Group	—		—			(43,536		)
Ending balance	$	19,149	$	16,143		$	15,155

- Definition

The entire disclosure for shareholders' equity, comprised of portions attributable to the parent entity and noncontrolling interest, if any, including other comprehensive income (as applicable). Including, but not limited to: (1) balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings; (2) accumulated balance for each classification of other comprehensive income and total amount of comprehensive income; (3) amount and nature of changes in separate accounts, including the number of shares authorized and outstanding, number of shares issued upon exercise and conversion, and for other comprehensive income, the adjustments for reclassifications to net income; (4) rights and privileges of each class of stock authorized; (5) basis of treasury stock, if other than cost, and amounts paid and accounting treatment for treasury stock purchased significantly in excess of market; (6) dividends paid or payable per share and in the aggregate for each class of stock for each period presented; (7) dividend restrictions and accumulated preferred dividends in arrears (in aggregate and per share amount); (8) retained earnings appropriations or restrictions, such as dividend restrictions; (9) impact of change in accounting principle, initial adoption of new accounting principle and correction of an error in previously issued financial statements; (10) shares held in trust for Employee Stock Ownership Plan (ESOP); (11) deferred compensation related to issuance of capital stock; (12) note received for issuance of stock; (13) unamortized discount on shares; (14) description, terms, and number of warrants or rights outstanding; (15) shares under subscription and subscription receivables, effective date of new retained earnings after quasi-reorganization and deficit eliminated by quasi-reorganization and, for a period of at least ten years after the effective date, the point in time from which the new retained dates; and (16) retroactive effective of subsequent change in capital structure.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 15

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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+ Details

Accumulated Comprehensive Income (Loss)

12 Months Ended

Dec. 31, 2012

Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]

Accumulated Comprehensive Income (Loss)

Comprehensive income consists of net income and other gains and losses affecting shareholders’ equity that are excluded from net income. For the Company, comprehensive income includes unrealized gains and losses on available for sale securities and foreign currency translation adjustments. The Company presents comprehensive income in its Consolidated Statements of Comprehensive Income. Components of Accumulated other comprehensive income (loss) consisted of:



	Foreign Currency Translation Adjustments			Unrealized Holding Gains (Losses) on Investments		Accumulated Other Comprehensive Income (Loss)
Total accumulated comprehensive income (loss) at January 1, 2010	(1,053		)	960		(93		)
Less: Total accumulated comprehensive loss attributable to noncontrolling interest at January 1, 2010	1,351			—		1,351
Total accumulated comprehensive income attributable to SEI Investments Company at January 1, 2010	$	298		$	960	$	1,258

Total comprehensive income	2,205			379		2,584
Less: Total comprehensive income attributable to noncontrolling interest	(685		)	—		(685		)
Total comprehensive income attributable to SEI Investments Company	$	1,520		$	379	$	1,899

Total accumulated comprehensive income at December 31, 2010	1,152			1,339		2,491
Less: Total accumulated comprehensive loss attributable to noncontrolling interest at December 31, 2010	666			—		666
Total accumulated comprehensive income attributable to SEI Investments Company at December 31, 2010	$	1,818		$	1,339	$	3,157

Total comprehensive loss	(3,195		)	1,235		(1,960		)
Less: Total comprehensive loss attributable to noncontrolling interest	703			—		703
Total comprehensive loss attributable to SEI Investments Company	$	(2,492	)	$	1,235	$	(1,257	)

Total accumulated comprehensive income at December 31, 2011	(2,043		)	2,574		531
Less: Total accumulated comprehensive loss attributable to noncontrolling interest at December 31, 2011	1,369			—		1,369
Total accumulated comprehensive income attributable to SEI Investments Company at December 31, 2011	$	(674	)	$	2,574	$	1,900

Total comprehensive income	5,904			255		6,159
Less: Total comprehensive income attributable to noncontrolling interest	(1,820		)	—		(1,820		)
Total comprehensive income attributable to SEI Investments Company	$	4,084		$	255	$	4,339

Total accumulated comprehensive income at December 31, 2012	3,861			2,829		6,690
Less: Total accumulated comprehensive income attributable to noncontrolling interest at December 31, 2012	(451		)	—		(451		)
Total accumulated comprehensive income attributable to SEI Investments Company at December 31, 2012	$	3,410		$	2,829	$	6,239

- Definition

The entire disclosure for comprehensive income, which includes, but is not limited to, 1) the amount of income tax expense or benefit allocated to each component of other comprehensive income, including reclassification adjustments, 2) the reclassification adjustments for each classification of other comprehensive income and 3) the ending accumulated balances for each component of comprehensive income.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187085-122770

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-Name Accounting Standards Codification

-Topic 220

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Reclassification Adjustments

-URI http://asc.fasb.org/extlink&oid=6522872

Reference 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 130

-Paragraph 14-26

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Employee Benefit Plan	12 Months Ended
Employee Benefit Plan	Dec. 31, 2012
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plan	Employee Benefit Plan The Company has a tax-qualified defined contribution plan (the Plan). The Plan provides retirement benefits, including provisions for early retirement and disability benefits, as well as a tax-deferred savings feature. After satisfying certain requirements, participants are vested in employer contributions at the time the contributions are made. All Company contributions are discretionary and are made from available profits. The Company contributed $5,168, $4,783, and $4,496 to the Plan in 2012, 2011, and 2010, respectively.

- Definition

The entire disclosure for pension and other postretirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5, 6, 7, 8

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

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-Name Statement of Financial Accounting Standard (FAS)

-Number 158

-Paragraph 7, 21, 22

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Implementation Guide (Q and A)

-Number FAS88

-Paragraph 63

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 03-2

-Paragraph 8

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

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-Number 87

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-Number 106

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-Number 132R

-Paragraph 5

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef

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-Number 132R

-Paragraph 5

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph h

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Number 132R

-Paragraph 5

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-Name FASB Staff Position (FSP)

-Number FAS106-2

-Paragraph 20, 21, 22

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-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 30

-Paragraph 26

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 8

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Reference 14: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-URI http://asc.fasb.org/topic&trid=2235017

+ Details

Commitments And Contingencies

12 Months Ended

Dec. 31, 2012

Commitments and Contingencies Disclosure [Abstract]

Commitments And Contingencies

Commitments and Contingencies

The Company leases certain of its facilities, data processing equipment, and software under non-cancelable operating leases, some which contain escalation clauses for increased taxes and operating expenses. The Company has entered into maintenance agreements primarily for its data processing equipment. Rent expense was $21,614, $19,760, and $17,210 in 2012, 2011, and 2010, respectively.

The aggregate noncancellable minimum commitments at December 31, 2012 are:



2013	$	15,138
2014	6,283
2015	2,807
2016	2,170
2017 and thereafter	9,193
	$	35,591

In the ordinary course of business, the Company from time to time enters into contracts containing indemnification obligations of the Company. These obligations may require the Company to make payments to another party upon the occurrence of certain events including the failure by the Company to meet its performance obligations under the contract. These contractual indemnification provisions are often standard contractual terms of the nature customarily found in the type of contracts entered into by the Company. In many cases, there are no stated or notional amounts included in the indemnification provisions. There are no amounts reflected on the Consolidated Balance Sheets as of December 31, 2012 and 2011 related to these indemnifications.

In the normal course of business, the Company is party to various claims and legal proceedings.

One of SEI's principal subsidiaries, SIDCO, has been named as a defendant in certain putative class action complaints (the Complaints) related to leveraged exchange traded funds (ETFs) advised by ProShares Advisors, LLC. The first complaint was filed on August 5, 2009 and the subsequent cases were all consolidated in the Southern District of New York. The Complaints are purportedly made on behalf of all persons that purchased or otherwise acquired shares in various ProShares leveraged ETFs pursuant or traceable to allegedly false and misleading registration statements, prospectuses and statements of additional information. The Complaints name as defendants ProShares Advisors, LLC; ProShares Trust; ProShares Trust II, SIDCO, and various officers and trustees to ProShares Advisors, LLC; ProShares Trust and ProShares Trust II. The Complaints allege that SIDCO was the distributor and principal underwriter for the various ProShares leveraged ETFs that were distributed to authorized participants and ultimately shareholders. The Complaints allege that the registration statements for the ProShares ETFs were materially false and misleading because they failed adequately to describe the nature and risks of the investments and claim that SIDCO is liable for these purportedly material misstatements and omissions under Section 11 of the Securities Act of 1933. Defendants moved to dismiss the amended complaint filed by plaintiffs, and on September 7, 2012, the District Court for the Southern District of New York issued an opinion dismissing with prejudice the plaintiffs' amended complaint. Plaintiffs filed with the Second Circuit Court of Appeals a notice of appeal of the District Court's decision. Plaintiffs-appellants filed their brief on December 17, 2012 and later filed a corrected brief on January 3, 2013. The brief of defendants-appellees was filed on February 1, 2013. While the outcome of this litigation is uncertain given its early phase, SEI believes that it has valid defenses to plaintiffs' claims and intends to defend the lawsuits vigorously.

SEI has been named in six lawsuits filed in Louisiana. Five lawsuits were filed in the 19th Judicial District Court for the Parish of East Baton Rouge, State of Louisiana. One of the five actions purports to set forth claims on behalf of a class and also names SPTC as a defendant and, as described below, was certified as a class in December 2012. Two of the other actions also name SPTC as a defendant. All five actions name various defendants in addition to SEI, and, in all five actions, the plaintiffs purport to bring a cause of action under the Louisiana Securities Act. The class action originally included a claim against SEI and SPTC for an alleged violation of the Louisiana Unfair Trade Practices Act. Two of the other five actions include claims for violations of the Louisiana Racketeering Act and possibly conspiracy. In addition, another group of plaintiffs have filed a lawsuit in the 23rd Judicial District Court for the Parish of Ascension, State of Louisiana, against SEI and SPTC and other defendants asserting claims of negligence, breach of contract, breach of fiduciary duty, violations of the uniform fiduciaries law, negligent misrepresentation, detrimental reliance, violations of the Louisiana Securities Act and Louisiana Racketeering Act and conspiracy. The underlying allegations in all the actions are purportedly related to the role of SPTC in providing back-office services to Stanford Trust Company. The petitions allege that SEI and SPTC aided and abetted or otherwise participated in the sale of “certificates of deposit” issued by Stanford International Bank. Two of the five actions filed in East Baton Rouge were removed to federal court and transferred by the Judicial Panel on Multidistrict Litigation to United States District Court for the Northern District of Texas. On August 31, 2011, the United States District Court for the Northern District of Texas issued an order and judgment that the causes of action alleged against SEI in the two removed actions were preempted by federal law and the Court dismissed these cases with prejudice. Plaintiffs appealed this ruling, and on March 19, 2012, a panel of the Court of Appeals for the Fifth Circuit reversed the decision of the United States District Court and remanded the actions for further proceedings. On July 18, 2012, SEI filed a petition for certiorari in the United States Supreme Court, seeking review of the decision by the United States Court of Appeals for the Eleventh Circuit to permit the claims against SEI to proceed. The Company believes that the trial court correctly concluded that the claims against SEI were barred by the federal Securities Litigation Uniform Standards Act and is requesting that the Supreme Court reinstate that dismissal. On January 18, 2013, the Supreme Court granted the petition for certiorari, and the Court will consider the case in the fall of this year.

SEI and SPTC filed exceptions in the class action pending in East Baton Rouge, which the Court granted in part and dismissed the claims under the Louisiana Unfair Trade Practices Act and denied in part as to the other exceptions. SEI and SPTC filed an answer to the East Baton Rouge class action; plaintiffs filed a motion for class certification; and SEI and SPTC also filed a motion for summary judgment against certain named plaintiffs which the Court stated will not be set for hearing until after the hearing on the class certification motion. The Court in the East Baton Rouge action held a hearing on class certification on September 20, 2012. By oral decision on December 5, 2012 and later entered in a judgment signed on December 17, 2012 that was subsequently amended, the Court in East Baton Rouge certified a class to be composed of persons who purchased any Stanford International Bank certificates of deposit (“SIB CDs”) in Louisiana between January 1, 2007 and February 13, 2009; persons who renewed any SIB CD in Louisiana between January 1, 2007 and February 13, 2009; or any person for whom the Stanford Trust Company purchased SIB CDs in Louisiana between January 1, 2007 and February 13, 2009. On January 30, 2013, SEI and SPTC filed motions for appeal from the judgments that stated SEI's and SPTC's intention to move to stay the litigation. On February 1, 2013, plaintiffs filed a Motion for Leave to File First Amended and Restated Class Action Petition in which they ask the Court to allow them to amend the petition in this case to add additional facts that were developed during discovery and adding claims against certain of SEI's insurance carriers. On February 5, 2013, the Court granted two of the motions for appeal and the motion for leave to amend. While the outcome of this litigation is uncertain given its early phase, SEI and SPTC believe that they have valid defenses to plaintiffs' claims and intend to defend the lawsuits vigorously.

The case filed in Ascension Parish was also removed to federal court and transferred by the Judicial Panel on Multidistrict Litigation to the Northern District of Texas. The schedule for responding to that complaint has not yet been established. The plaintiffs in the remaining two cases in East Baton Rouge have granted SEI an extension to respond to the filings.

Because of the uncertainty of the make-up of the classes, the outcome of the proceeding in the U.S. Supreme Court, the specific theories of liability that may survive a motion for summary judgment or other dispositive motion, the lack of discovery regarding damages, causation, mitigation and other aspects that may ultimately bear upon loss, the Company is not reasonably able to provide an estimate of loss, if any, with respect to the foregoing lawsuits.

- Definition

The entire disclosure for commitments and contingencies.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Interpretation (FIN)

-Number 14

-Paragraph 3

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

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-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.25)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Paragraph 2

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 9, 10, 11, 12

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Income Taxes

12 Months Ended

Dec. 31, 2012

Income Tax Disclosure [Abstract]

Income Taxes

The federal and state and foreign income tax provision is summarized as follows:



Year Ended December 31,	2012			2011			2010
Current
Federal	$	112,247		$	99,448		$	116,388
State	5,284			7,067			8,698
Foreign	4,511			4,603			3,365
	122,042			111,118			128,451
Deferred, including current deferred
Federal	(2,708		)	(2,317		)	6,085
State	(2,199		)	2,477			1,509
Foreign	3,970			6			—
	(937		)	166			7,594
Income taxes attributable to the Noncontrolling interest	357			553			416
Total income taxes	$	121,462		$	111,837		$	136,461

Annual tax provisions include amounts considered sufficient to pay assessments that may result from examination of prior year tax returns; however, the amount ultimately paid upon resolution of issues raised may differ materially from the amount accrued. The examination and the resolution process may last longer than one year.

The components of Net income before income taxes are summarized as follows:



Year Ended December 31,	2012		2011		2010
Domestic	$	319,907	$	309,391	$	360,937
Foreign	8,046		6,852		6,795
	$	327,953	$	316,243	$	367,732

The effective income tax rate differs from the federal income tax statutory rate due to the following:



Year Ended December 31,	2012		2011		2010
Statutory rate	35.0	%	35.0	%	35.0	%
State taxes, net of Federal tax benefit	1.0		2.0		2.0
Foreign tax expense and tax rate differential	1.6		0.6		0.4
Research and development tax credit	—		(0.7	)	(0.5	)
Domestic Production Activities Deduction	(0.6	)	(0.7	)	—
Valuation allowance on PA loss carryforwards	(0.3	)	—		—
Domestic Production Activities Deduction, prior years, net	—		(1.5	)	—
Net change in uncertain tax positions (1)	0.5		0.4		0.2
Other, net	(0.3	)	0.1		(0.1	)
	36.9	%	35.2	%	37.0	%

(1) For 2012, 0.15 percent relates to federal issues mainly associated with compilation of foreign tax credits, 0.33 percent relates to state tax issues and the remaining 0.02 percent relates to foreign tax issues. For 2011, 0.25 percent relates to federal issues, 0.14 percent relates to state tax issues and the remaining 0.01 percent relates to foreign tax issues. For 2010, 0.14 percent relates to federal issues and the remaining 0.06 percent relates to state tax issues.

Undistributed earnings of the Company’s foreign subsidiaries, except for SEI Asset Korea Co., Ltd. (SEI AK), amounted to approximately $47,385 at December 31, 2012. Those earnings are considered to be indefinitely reinvested and, accordingly, no U.S. federal and state income taxes have been provided thereon. Upon distribution of those earnings, in the form of dividends or otherwise, the Company would be subject to both U.S. income taxes, subject to an adjustment for foreign tax credits, and withholding taxes payable to the various foreign countries. Determination of the amount of unrecognized deferred U.S. income tax liability is not practicable because of the complexities associated with its hypothetical calculation, including the availability, or lack thereof, of foreign tax credits to reduce a portion of the U.S. liability. The Company no longer considers the earnings of SEI AK to be indefinitely reinvested and, therefore, has accrued U.S. deferred taxes on the cumulative undistributed earnings (See Note 15).

Deferred income taxes for 2012, 2011, and 2010 reflect the impact of temporary differences between the amount of assets and liabilities for financial reporting purposes and such amounts as measured by tax laws and regulations.

The net deferred income tax liability is comprised of:



Year Ended December 31,	2012			2011
Current deferred income taxes:
Gross assets	$	2,012		$	1,151
Gross liabilities	—			(1		)
	2,012			1,150
Valuation allowance	—			—
	2,012			1,150
Long-term deferred income taxes:
Gross assets	63,129			63,374
Gross liabilities	(149,708		)	(148,540		)
	(86,579		)	(85,166		)
Valuation allowance	(6,879		)	(8,585		)
	(93,458		)	(93,751		)
Net deferred income tax liability	$	(91,446	)	$	(92,601	)

The valuation allowances against deferred tax assets at December 31, 2012 and 2011 are related to state net operating losses from certain domestic subsidiaries. Certain state tax statutes significantly limit the utilization of net operating losses for domestic subsidiaries. Furthermore, these net operating losses cannot be used to offset the net income of other subsidiaries.

The tax effect of significant temporary differences representing deferred tax liabilities is:



Year Ended December 31,	2012			2011
Difference in financial reporting and income tax depreciation methods	$	(10,104	)	$	(13,600	)
Reserves not currently deductible	325			374
Capitalized software currently deductible for tax purposes, net of amortization	(137,467		)	(139,455		)
State deferred income taxes	5,943			6,717
Revenue and expense recognized in different periods for financial reporting and income tax purposes	4,397			3,149
Unrealized holding gain on investments	(1,428		)	(927		)
Stock-based compensation expense	42,133			43,879
State net operating loss carryforward	13,883			14,485
Valuation allowance on deferred tax assets	(6,879		)	(8,585		)
Federal benefit of state tax deduction for uncertain tax positions	2,359			1,725
Foreign currency exchange	(39		)	(363		)
Foreign deferred including taxes on cumulative undistributed earnings of SEI AK	(4,569		)	—
Net deferred income tax liability	$	(91,446	)	$	(92,601	)

The Company recognizes uncertain tax positions in accordance with the applicable accounting guidance and adjusts these liabilities when management’s judgment changes as a result of the evaluation of new information not previously available. Due to the complexity of some of these uncertainties, the ultimate resolution may result in a payment that is materially different than from our current estimate of the tax liabilities. The Company’s total unrecognized tax benefit, not including interest and penalties, as of December 31, 2012 was $11,553, of which $9,965 would affect the effective tax rate if the Company were to recognize the tax benefit. The gross amount of uncertain tax liability of $5,291 which is expected to be paid within one year is included in Current liabilities while the remaining amount of $7,032 is included in Other long-term liabilities on the accompanying Consolidated Balance Sheets. During the year ended December 31, 2012, the Company recognized $1,944 of previously unrecognized tax benefits relating to the lapse of the statute of limitation for certain state filings.

The Company files a consolidated federal income tax return and separate income tax returns with various states. Certain subsidiaries of the Company file tax returns in foreign jurisdictions. The Company is no longer subject to U.S. federal income tax examination for years before 2009 and is no longer subject to state, local or foreign income tax examinations by authorities for years before 2006.

A reconciliation of the beginning and ending amount of unrecognized tax benefit is as follows:



	2012			2011			2010
Balance as of January 1	$	9,410		$	5,723		$	4,989
Tax positions related to current year:
Gross additions	2,196			2,392			1,372
Gross reductions	—			—			—
	2,196			2,392			1,372
Tax positions related to prior years:
Gross additions	1,990			1,992			—
Gross reductions	—			—			(104		)
	1,990			1,992			(104		)
Settlements	(99		)	—			(102		)
Lapses on statute of limitations	(1,944		)	(697		)	(432		)
Balance as of December 31	$	11,553		$	9,410		$	5,723

The above reconciliation of the gross unrecognized tax benefit will differ from the amount which would affect the effective tax rate because of the recognition of the federal and state tax benefits.

The Company classifies all interest and penalties as income tax expense. The Company has recorded $770, $634 and $690 in liabilities for tax related interest and penalties in 2012, 2011, and 2010, respectively.

The Company estimates it will recognize $5,291 of unrecognized tax benefits within the next twelve months due to lapses on the statute of limitation and settlements.

The Company includes its direct and indirect subsidiaries in its U.S. consolidated federal income tax return. The Company’s tax sharing allocation agreement provides that any subsidiary having taxable income will pay a tax liability equivalent to what that subsidiary would have paid if it filed a separate income tax return. If the separately calculated federal income tax provision for any subsidiary results in a tax loss, the current benefit resulting from such loss, to the extent utilizable on a separate return basis, is accrued and paid to that subsidiary.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319

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-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(h))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph h

-Article 4

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+ Details

Business Segment Information

12 Months Ended

Dec. 31, 2012

Segment Reporting [Abstract]

Business Segment Information

The Company’s reportable business segments are:

Private Banks – provides investment processing and investment management programs to banks and trust institutions worldwide, independent wealth advisers located in the United Kingdom, and financial advisors in Canada;

Investment Advisors – provides investment management programs to affluent investors through a network of independent registered investment advisors, financial planners, and other investment professionals in the United States;

Institutional Investors – provides investment management programs and administrative outsourcing solutions to retirement plan sponsors, hospitals, and not-for-profit organizations worldwide;

Investment Managers – provides investment operations outsourcing solutions to investment managers, fund companies and banking institutions located in the United States, and to investment managers worldwide of alternative asset classes such as hedge funds, funds of hedge funds, and private equity funds across both registered and partnership structures; and

Investments in New Businesses – provides investment management programs to ultra-high-net-worth families residing in the United States through the SEI Wealth Network® and conducts other research and development activities.

In 2012, 2011 and 2010, no single customer accounted for more than ten percent of revenues in any business segment.

The following tables highlight certain financial information about each of the Company’s business segments for the years ended December 31, 2012, 2011, and 2010:



	Private Banks			Investment Advisors			Institutional Investors			Investment Managers			Investments In New Businesses			Total
	For the Year Ended December 31, 2012
Revenues	$	364,788		$	202,703		$	227,889		$	193,484		$	3,658		$	992,522
Expenses	357,001			120,146			116,546			127,525			14,954			736,172
Operating profit (loss)	$	7,787		$	82,557		$	111,343		$	65,959		$	(11,296	)	$	256,350
Profit margin	2		%	41		%	49		%	34		%	N/A			26		%



	Private Banks			Investment Advisors			Institutional Investors			Investment Managers			Investments In New Businesses			Total
	For the Year Ended December 31, 2011
Revenues	$	348,122		$	189,780		$	210,027		$	177,975		$	3,823		$	929,727
Expenses	339,339			110,438			106,585			115,963			11,559			683,884
Operating profit (loss)	$	8,783		$	79,342		$	103,442		$	62,012		$	(7,736	)	$	245,843
Profit margin	3		%	42		%	49		%	35		%	N/A			26		%



	Private Banks			Investment Advisors			Institutional Investors			Investment Managers			Investments In New Businesses			Total
	For the Year Ended December 31, 2010
Revenues	$	346,668		$	183,378		$	206,531		$	160,159		$	4,099		$	900,835
Expenses	310,633			110,388			106,934			103,421			12,676			644,052
Operating profit (loss)	$	36,035		$	72,990		$	99,597		$	56,738		$	(8,577	)	$	256,783
Profit margin	10		%	40		%	48		%	35		%	N/A			29		%

A reconciliation of the total reported for the business segments to income from operations in the Consolidated Statements of Operations for the years ended December 31, 2012, 2011, and 2010 is as follows:



Year Ended December 31,	2012			2011			2010
Total operating profit from segments above	$	256,350		$	245,843		$	256,783
Corporate overhead expenses	(45,759		)	(43,398		)	(40,715		)
Noncontrolling interest reflected in segments	975			1,620			1,465
Income from operations	$	211,566		$	204,065		$	217,533

The following tables provide additional information for the years ended December 31, 2012, 2011, and 2010 pertaining to our business segments:



	Capital Expenditures						Depreciation
Year Ended December 31,	2012		2011		2010		2012		2011		2010
Private Banks	$	32,509	$	35,045	$	32,982	$	15,226	$	15,648	$	15,704
Investment Advisors	11,193		11,933		11,691		1,981		2,251		2,384
Institutional Investors	2,781		2,059		2,601		1,012		1,079		1,170
Investment Managers	5,494		3,081		3,659		1,914		1,809		1,891
Investments in New Businesses	632		577		608		1,716		114		148
Total from business segments	$	52,609	$	52,695	$	51,541	$	21,849	$	20,901	$	21,297
Corporate Overhead	1,465		530		799		737		570		605
	$	54,074	$	53,225	$	52,340	$	22,586	$	21,471	$	21,902



	Amortization
Year Ended December 31,	2012		2011		2010
Private Banks	$	22,218	$	18,081	$	15,100
Investment Advisors	7,167		6,201		5,467
Institutional Investors	1,208		864		1,213
Investment Managers	804		580		820
Investments in New Businesses	1,249		433		477
Total from business segments	$	32,646	$	26,159	$	23,077
Corporate Overhead	612		1,129		971
	$	33,258	$	27,288	$	24,048



	Total Assets
	2012		2011
Private Banks	$	481,602	$	457,333
Investment Advisors	120,255		119,053
Institutional Investors	99,461		80,133
Investment Managers	118,221		95,760
Investments in New Businesses	5,846		5,962
Total from business segments	$	825,385	$	758,241
Corporate Overhead (1)	484,439		536,318
	$	1,309,824	$	1,294,559

(1) Unallocated assets primarily consist of cash and cash equivalents, marketable securities, and certain other shared services assets.

The following table presents revenues based on the location of the use of the products or services:



For the Year Ended December 31,	2012		2011		2010
United States	$	843,407	$	785,506	$	767,068
International operations	149,115		144,221		133,767
	$	992,522	$	929,727	$	900,835

The following table presents assets based on their location:



	2012		2011
United States	$	1,066,451	$	1,098,643
International operations	243,373		195,916
	$	1,309,824	$	1,294,559

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

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+ Details

Related Party Transactions	12 Months Ended
Related Party Transactions	Dec. 31, 2012
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions The Company, either by itself or through its wholly-owned subsidiaries, is a party to Investment Advisory and Administration Agreements with regulated investment companies (RICs) and other investment products which are administered by the Company. These investment products are offered to clients of the Company and its subsidiaries. Under the Investment Advisory and Administration Agreements, the Company receives a fee for providing investment advisory, administrative, and accounting services. The investment advisory and administration fee is a fixed percentage, referred to as basis points, of the average daily net assets, subject to certain limitations. Investment advisory and administration fees received by the Company totaled $380,645, $364,602 and $354,341 in 2012, 2011 and 2010, respectively. The Company is also a party to various agreements with several RICs which are advised and/or administered by the Company. The Company receives a fee for providing shareholder, administrative and distribution services pursuant to the provisions of various shareholder service, administrative service, and distribution plans adopted by the RICs. These fees totaled $37,827, $39,017 and $36,007 in 2012, 2011 and 2010, respectively. A portion of the transaction costs incurred by the RICs for securities transactions are directed to the Company’s broker-dealer subsidiary in its capacity as an introducing broker-dealer. The Company recognized $1,213, $2,772 and $4,875 in commissions during 2012, 2011 and 2010, respectively.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

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-Number 210

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+ Details

Sale of SEI Asset Korea	12 Months Ended
Sale of SEI Asset Korea	Dec. 31, 2012
Sale of SEI Asset Korea [Abstract]
Sale of SEI Asset Korea	Sale of SEI Asset Korea On July 31, 2012, the Company, MetLife International Holdings, Inc. (MetLife) and International Finance Corporation (IFC) entered into a definitive agreement with Baring Asset Management Limited to sell all ownership interests in SEI AK. SEI AK is located in South Korea and provides domestic equity and fixed income investment management services to financial institutions and pension funds. Consummation of the acquisition of SEI AK under the definitive agreement is subject to regulatory approvals and other customary closing conditions. The Company's ownership interest in SEI AK is 56.1 percent as of December 31, 2012. The Company consolidates the assets, liabilities and operations of SEI AK in its Consolidated Financial Statements. The ownership interests in SEI AK for MetLife and IFC is reflected in Noncontrolling interest in the Consolidated Financial Statements. The operating results of SEI AK are included in the Private Banks business segment. Upon closing of the agreement, the then current cash balance of SEI AK will be distributed to the Company, Metlife and IFC in accordance with the ownership interests. As of December 31, 2012, SEI AK had total corporate assets of $54,783, of which $48,306 is included in Cash and Cash equivalents on the Consolidated Balance Sheet. All other accounts of SEI AK are not material to any financial statement line item in the Consolidated Financial Statements. The Company did not provide U.S. deferred taxes on the undistributed earnings of SEI AK since its inception because those earnings were considered to be indefinitely reinvested. As a result of the potential sale of SEI AK, the Company no longer considers the undistributed earnings of SEI AK to be indefinitely reinvested and, therefore, accrued $4,815 for U.S. deferred taxes on the cumulative undistributed earnings during 2012. If the requisite regulatory approvals are obtained, the other conditions to closing are satisfied or waived and the transaction is consummated, then the Company expects to recognize a net after tax gain on the sale of its shares of SEI AK depending upon revenue during a pre-closing measurement period and specified revenues during three one-year periods after the closing.

- Definition

The entire disclosure for the facts and circumstances leading to the completed or expected disposal, manner and timing of disposal, the gain (loss) recognized in the income statement and the income statement caption that includes that gain (loss), amounts of revenues and pretax profit or loss reported in discontinued operations, the segment in which the disposal group was reported, and the classification (whether sold or classified as held for sale) and carrying value of the assets and liabilities comprising the disposal group. Includes all disposal groups, including those classified as components of the entity (discontinued operations).

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+ Details

Quarterly Financial Data

12 Months Ended

Dec. 31, 2012

Quarterly Financial Data [Abstract]

Quarterly Financial Data

Quarterly Financial Data (Unaudited)



	For the Three Months Ended
2012	March 31			June 30			Sept. 30			Dec. 31
Revenues	$	237,898		$	241,237		$	251,752		$	261,635
Income before income taxes	$	79,950		$	78,501		$	83,501		$	87,544
Net income attributable to SEI	$	49,965		$	49,555		$	50,743		$	56,585
Basic earnings per share	$	0.28		$	0.28		$	0.29		$	0.33
Diluted earnings per share	$	0.28		$	0.28		$	0.29		$	0.32

Effective income tax rate	37.2		%	36.6		%	39.0		%	35.0		%

Total SIV-related gains	$	2,882		$	1,072		$	3,389		$	5,897
Diluted earnings per share (1)	$	0.01		$	—		$	0.01		$	0.02

(1) Attributable to SIV-related gains.



	For the Three Months Ended
2011	March 31			June 30			Sept. 30			Dec. 31
Revenues	$	232,493		$	237,760		$	233,227		$	226,247
Income before income taxes	$	92,164		$	82,820		$	74,900		$	68,603
Net income attributable to SEI	$	57,728		$	53,603		$	49,232		$	44,396
Basic earnings per share	$	0.31		$	0.29		$	0.27		$	0.25
Diluted earnings per share	$	0.31		$	0.29		$	0.27		$	0.25

Effective income tax rate	37.1		%	34.7		%	33.8		%	34.7		%

Total SIV-related gains (losses)	$	6,864		$	(1,944	)	$	(792	)	$	(738	)
Diluted earnings per share (2)	$	0.02		$	0.01		$	—		$	—

(2) Attributable to SIV-related gains (losses).

- Definition

The entire disclosure for the quarterly financial data in the annual financial statements. The disclosure may include a tabular presentation of financial information for each fiscal quarter for the current and previous year, including revenues, gross profit, income or loss before extraordinary items and earnings per share data. It also includes an indication if the information in the note is unaudited, comments on the aggregate effect of year-end adjustments, and an explanation of matters or transactions that affect comparability or are pertinent to an understanding of the information furnished.

+ References+ Details

Schedule II - Valuation And Qualifying Accounts And Reserves

12 Months Ended

Dec. 31, 2012

Valuation and Qualifying Accounts [Abstract]

Schedule II - Valuation And Qualifying Accounts And Reserves



Schedule II - Valuation and Qualifying Accounts and Reserves								SEI Investments Company and Subsidiaries

Year Ended December 31,			Additions
Description	Balance at Beginning of Year		Charged to Costs and Expenses			Charged to Other Accounts		(Deductions)			Balance at End of Year
Allowance for doubtful accounts:
2012	$	924	$	—		$	—	$	(119	)	$	805
2011	1,195		—			—		(271		)	924
2010	3,348		—			—		(2,153		)	1,195
Deferred income tax valuation allowance:
2012	$	8,585	$	(1,706	)	$	—	$	—		$	6,879
2011	9,008		(423		)	—		—			8,585
2010	6,217		1,443			1,348		—			9,008

Summary Of Significant Accounting Policies (Policy)

12 Months Ended

Dec. 31, 2012

Accounting Policies [Abstract]

Nature Of Operations

Nature of Operations

Principles of Consolidation

Variable Interest Entities

Management's Use of Estimates

Management’s Use of Estimates

Revenue Recognition

Cash and Cash Equivalents

The Company considers investment instruments purchased with an original maturity of three months or less to be cash equivalents.

Allowance for Doubtful Accounts

Allowances for Doubtful Accounts

Concentration of Credit Risk

Property, Plant and Equipment

Property and Equipment

Marketable Securities

Fair Value of Financial Instruments

See Note 5 for information on related disclosures regarding fair value measurements.

Capitalized Software

Income Taxes

Foreign Currency Translation

Transaction gains and losses from exchange rate fluctuations are included in the results of operations in the periods in which they occur.

Earnings Per Share

Earnings Per Common Share



	For the Year Ended December 31, 2012
	Net income attributable to SEI (Numerator)		Shares (Denominator)	Per-Share Amount
Basic earnings per common share	$	206,848	174,295	$	1.19
Dilutive effect of stock options	—		1,577
Diluted earnings per common share	$	206,848	175,872	$	1.18



	For the Year Ended December 31, 2011
	Net income attributable to SEI (Numerator)		Shares (Denominator)	Per-Share Amount
Basic earnings per common share	$	204,959	182,547	$	1.12
Dilutive effect of stock options	—		1,580
Diluted earnings per common share	$	204,959	184,127	$	1.11



	For the Year Ended December 31, 2010
	Net income attributable to SEI (Numerator)		Shares (Denominator)	Per-Share Amount
Basic earnings per common share	$	231,687	188,468	$	1.23
Dilutive effect of stock options	—		1,853
Diluted earnings per common share	$	231,687	190,321	$	1.22

Stock-based Compensation

Stock-Based Compensation

Reclassifications

Certain prior year amounts have been reclassified to conform to current year presentation.

Investments in Equity Method Investments

The Company accounts for its interest in LSV using the equity method because of its less than 50 percent ownership. The Company’s interest in the net assets of LSV is reflected in Investment in unconsolidated affiliates on the accompanying Consolidated Balance Sheets and its interest in the earnings of LSV is reflected in Equity in earnings of unconsolidated affiliates on the accompanying Consolidated Statements of Operations.

Trading Securities

Securities Owned

Unremitted Earnings in Foreign Investment

Those earnings are considered to be indefinitely reinvested and, accordingly, no U.S. federal and state income taxes have been provided thereon. Upon distribution of those earnings, in the form of dividends or otherwise, the Company would be subject to both U.S. income taxes, subject to an adjustment for foreign tax credits, and withholding taxes payable to the various foreign countries. Determination of the amount of unrecognized deferred U.S. income tax liability is not practicable because of the complexities associated with its hypothetical calculation, including the availability, or lack thereof, of foreign tax credits to reduce a portion of the U.S. liability.

Summary Of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2012

Accounting Policies [Abstract]

Calculation Of Basic And Diluted Earnings Per Share

The calculations of basic and diluted earnings per share for 2012, 2011, and 2010 are:



	For the Year Ended December 31, 2012
	Net income attributable to SEI (Numerator)		Shares (Denominator)	Per-Share Amount
Basic earnings per common share	$	206,848	174,295	$	1.19
Dilutive effect of stock options	—		1,577
Diluted earnings per common share	$	206,848	175,872	$	1.18



	For the Year Ended December 31, 2011
	Net income attributable to SEI (Numerator)		Shares (Denominator)	Per-Share Amount
Basic earnings per common share	$	204,959	182,547	$	1.12
Dilutive effect of stock options	—		1,580
Diluted earnings per common share	$	204,959	184,127	$	1.11



	For the Year Ended December 31, 2010
	Net income attributable to SEI (Numerator)		Shares (Denominator)	Per-Share Amount
Basic earnings per common share	$	231,687	188,468	$	1.23
Dilutive effect of stock options	—		1,853
Diluted earnings per common share	$	231,687	190,321	$	1.22

Investment In Unconsolidated Affiliates Investment In Unconsolidated Affiliates (Tables)

12 Months Ended

Dec. 31, 2012

Condensed Financial Statements of LSV [Abstract]

Condensed Statement Of Operations Of LSV



Condensed Statement of Operations Year ended December 31,	2012		2011		2010
Revenues	$	296,261	$	296,397	$	273,381
Net income	$	250,165	$	257,519	$	239,981

Condensed Balance Sheets Of LSV



Condensed Balance Sheets December 31,	2012		2011
Current assets	$	145,367	$	136,601
Non-current assets	3,120		3,880
Total assets	$	148,487	$	140,481

Current liabilities	$	17,869	$	13,933
Partners’ capital	130,618		126,548
Total liabilities and partners’ capital	$	148,487	$	140,481

Composition Of Certain Financial Statement Captions (Tables)

12 Months Ended

Dec. 31, 2012

Items Included in Consolidated Statement of Financial Condition [Abstract]

Receivables

Receivables on the accompanying Consolidated Balance Sheets consist of:



	2012			2011
Trade receivables	$	46,650		$	37,822
Fees earned, not billed	116,019			92,916
Other receivables	9,870			12,295
	172,539			143,033
Less: Allowance for doubtful accounts	(805		)	(924		)
Receivables, net	$	171,734		$	142,109

Property And Equipment

Property and Equipment on the accompanying Consolidated Balance Sheets consists of:



	2012			2011
Buildings	$	137,751		$	136,949
Equipment	66,167			64,256
Land	9,929			9,929
Purchased software	91,468			77,971
Furniture and fixtures	18,535			17,999
Leasehold improvements	5,037			4,558
Construction in progress	112			339
	328,999			312,001
Less: Accumulated depreciation	(201,418		)	(182,453		)
Property and Equipment, net	$	127,581		$	129,548

Accrued Liabilities

Accrued Liabilities on the accompanying Consolidated Balance Sheets consist of:



	2012		2011
Accrued employee compensation	$	63,996	$	48,112
Accrued employee benefits and other personnel	7,299		5,408
Accrued consulting, outsourcing and professional fees	16,676		17,477
Accrued brokerage fees	5,733		8,665
Accrued sub-advisory, distribution and other asset management fees	17,548		17,091
Accrued dividend payable	—		26,518
Other accrued liabilities	27,053		23,773
Accrued liabilities	$	138,305	$	147,044

- Definition

Tabular disclosure of the useful life and salvage value of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.

+ References+ Details

Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2012

Fair Value Disclosures [Abstract]

Fair Value Of Certain Financial Assets And Liabilities

The fair value of certain financial assets and liabilities of the Company was determined using the following inputs:



			December 31, 2012
			Fair Value Measurements at Reporting Date Using
	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets
Equity available-for-sale securities	$	15,926	$	15,926	$	—	$	—
Fixed-income available-for-sale securities	59,943		—		59,943		—
Fixed income securities owned	20,088		—		20,088		—
Trading securities	5,909		4,706		—		1,203
	$	101,866	$	20,632	$	80,031	$	1,203



			December 31, 2011
			Fair Value Measurements at Reporting Date Using
	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets
Equity available-for-sale securities	$	8,010	$	8,010	$	—	$	—
Fixed-income available-for-sale securities	74,998		—		74,998		—
Fixed income securities owned	20,949		—		20,949		—
Trading securities	56,325		3,702		—		52,623
	$	160,282	$	11,712	$	95,947	$	52,623

Reconciliation For All Assets And Liabilities Of The Company Measured At Fair Value On A Recurring Basis Using Significant Unobservable Inputs (Level 3)



	Trading Securities
Balance, January 1, 2011	$	100,645
Purchases	1,215
Issuances	—
Principal prepayments and settlements	(17,921		)
Sales	(34,706		)
Total gains or (losses) (realized/unrealized):
Included in earnings	3,390
Included in other comprehensive income	—
Transfers in and out of Level 3	—
Balance, December 31, 2011	$	52,623
Purchases	13
Issuances	—
Principal prepayments and settlements	(10,728		)
Sales	(53,920		)
Total gains or (losses) (realized/unrealized):
Included in earnings	13,215
Included in other comprehensive income	—
Transfers in and out of Level 3	—
Balance, December 31, 2012	$	1,203

- Definition

Tabular disclosure of the amount of gains or losses for the period included in earnings or resulted in a change to net assets, have arisen from the use of significant unobservable inputs (level 3) to measure the fair value of assets, liabilities, and financial instruments classified in shareholders' equity.

+ References+ Details

Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2012

Marketable Securities [Abstract]

Investments Available For Sale

Investments available for sale classified as non-current assets consist of:



	At December 31, 2012
	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Fair Value
SEI-sponsored mutual funds	$	12,953	$	376	$	(13	)	$	13,316
Equities and other mutual funds	2,610		—		—			2,610
Debt securities	55,923		4,020		—			59,943
	$	71,486	$	4,396	$	(13	)	$	75,869



	At December 31, 2011
	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Fair Value
SEI-sponsored mutual funds	$	8,243	$	48	$	(360	)	$	7,931
Other mutual funds	69		10		—			79
Debt securities	70,604		4,394		—			74,998
	$	78,916	$	4,452	$	(360	)	$	83,008

Trading Securities

Trading securities of the Company consist of:



	At December 31, 2012
	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Fair Value
LSV-sponsored mutual funds	$	2,049	$	2,657	$	—		$	4,706
Other investments	1,228		—		(25		)	1,203
	$	3,277	$	2,657	$	(25	)	$	5,909



	At December 31, 2011
	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Fair Value
SIV securities	$	146,363	$	—	$	(94,955	)	$	51,408
LSV-sponsored mutual funds	2,049		1,653		—			3,702
Other investments	1,215		—		—			1,215
	$	149,627	$	1,653	$	(94,955	)	$	56,325

- Definition

Tabular disclosure of available-for-sale securities which includes, but is not limited to, changes in the cost basis and fair value, fair value and gross unrealized gain (loss), fair values by type of security, contractual maturity and classification, amortized cost basis, contracts to acquire securities to be accounted for as available-for-sale, debt maturities, transfers to trading, change in net unrealized holding gain (loss) net of tax, continuous unrealized loss position fair value, aggregate losses qualitative disclosures, other than temporary impairment (OTTI) losses or other disclosures related to available for sale securities.

+ References

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- Definition

Tabular disclosure of trading securities (and certain trading assets) which consist of all investments in certain debt and equity securities (and other assets) that are bought and held principally for the purpose of selling them in the near term (thus held for only a short period of time) or for which an entity has elected the fair value option. Trading generally reflects active and frequent buying and selling, and trading securities are generally used with the objective of generating profits on short-term differences in price, but this category of investments may also include items which are not intended to be sold in the near term or for which the fair value option has been elected.

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-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 17

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-Name Statement of Financial Accounting Standard (FAS)

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+ Details

Shareholders' Equity (Tables)

12 Months Ended

Dec. 31, 2012

Stockholders' Equity Note [Abstract]

Assumptions Used In The Weighted Average Fair Value Of The Stock Options Granted

The weighted average fair value of the Company’s stock options granted during 2012, 2011 and 2010 were $6.73, $5.70 and $9.65, respectively, using the following assumptions:



	2012		2011		2010
Expected term (in years)	6.75		7.65		7.45
Expected volatility	34.90	%	40.43	%	36.35	%
Expected dividend yield	1.46	%	1.90	%	0.84	%
Risk-free interest rate	1.03	%	1.66	%	3.01	%

Stock-based Compensation Expense

The Company recognized stock-based compensation expense in its Consolidated Financial Statements in 2012, 2011 and 2010 as follows:



	2012			2011			2010
Stock-based compensation expense	$	15,736		$	14,112		$	26,783
Less: Deferred tax benefit	(5,650		)	(5,332		)	(10,068		)
Stock-based compensation expense, net of tax	$	10,086		$	8,780		$	16,715

Stock Option Plans

This table presents certain information relating to the Company’s stock option plans for 2012, 2011, and 2010:



	Number of Shares		Weighted Avg. Price
Balance as of December 31, 2009	28,964,000		$	20.09
Granted	2,883,000		23.84
Exercised	(1,633,000	)	16.04
Expired or canceled	(2,333,000	)	23.68
Balance as of December 31, 2010	27,881,000		$	20.42
Granted	2,534,000		15.77
Exercised	(1,364,000	)	16.37
Expired or canceled	(2,008,000	)	22.07
Balance as of December 31, 2011	27,043,000		$	20.06
Granted	2,470,000		22.40
Exercised	(3,136,000	)	15.19
Expired or canceled	(767,000	)	22.61
Balance as of December 31, 2012	25,610,000		$	20.81

Exercisable as of December 31, 2012	9,760,000		$	18.11
Available for future grant as of December 31, 2012	2,569,000

Stock Options Outstanding And Exercisable

This table summarizes information relating to all options outstanding and exercisable at December 31, 2012:



				Options Outstanding at December 31, 2012				Options Exercisable at December 31, 2012
Range of Exercise Prices (Per Share)				Number of Shares	Weighted Average Exercise Price (Per Share)		Weighted Average Remaining Contractual Life (Years)	Number of Shares	Weighted Average Exercise Price (Per Share)		Weighted Average Remaining Contractual Life (Years)
$	14.62	-	15.52	5,065,000	$	14.69	4.36	3,153,000	$	14.73	3.36
15.77		-	17.65	5,999,000	16.87		7.81	1,647,000	17.63		6.92
18.00		-	21.55	4,981,000	20.37		2.57	4,945,000	20.39		2.51
22.45		-	23.86	5,143,000	23.19		8.94	—	—		—
27.03		-	32.49	4,422,000	30.88		4.46	15,000	27.03		4.00
				25,610,000				9,760,000

Common Stock Buyback

The following table provides the total number of shares repurchased and the related total costs in 2012, 2011 and 2010:



Year	Total Number of Shares Repurchased	Total Cost
2012	7,528,000	$	155,264
2011	11,109,000	211,165
2010	5,814,000	120,982

Reconciliation Of Noncontrolling Interest On The Consolidated Statements Of Changes In Equity

The following table provides a reconciliation of Noncontrolling interest on the Consolidated Statements of Changes in Equity:



Year Ended December 31,	2012		2011			2010
Noncontrolling interest
Beginning balance	$	16,143	$	15,155		$	121,895
Net income attributable to noncontrolling interest	1,186		1,691			1,633
Foreign currency translation adjustments	1,820		(703		)	685
Deconsolidation of LSV	—		—			(65,522		)
Deconsolidation of LSV Employee Group	—		—			(43,536		)
Ending balance	$	19,149	$	16,143		$	15,155

- Definition

Tabular disclosure of an entity's treasury stock, including the average cost per share, carrying basis for each class of treasury stock, description of share repurchase program authorized by an entity's board of directors, the number of shares repurchased, the cost of the shares repurchased, the remaining maximum dollar value of shares available for repurchase under the program, the treatment of the purchase price in excess of the current market value, number of shares held for each class of treasury stock, and other information necessary to a fair presentation.

+ References+ Details

Accumulated Comprehensive Income (Loss) (Tables)

12 Months Ended

Dec. 31, 2012

Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]

Schedule Of Accumulated Other Comprehensive Income (Loss), Net Of Tax

Components of Accumulated other comprehensive income (loss) consisted of:



	Foreign Currency Translation Adjustments			Unrealized Holding Gains (Losses) on Investments		Accumulated Other Comprehensive Income (Loss)
Total accumulated comprehensive income (loss) at January 1, 2010	(1,053		)	960		(93		)
Less: Total accumulated comprehensive loss attributable to noncontrolling interest at January 1, 2010	1,351			—		1,351
Total accumulated comprehensive income attributable to SEI Investments Company at January 1, 2010	$	298		$	960	$	1,258

Total comprehensive income	2,205			379		2,584
Less: Total comprehensive income attributable to noncontrolling interest	(685		)	—		(685		)
Total comprehensive income attributable to SEI Investments Company	$	1,520		$	379	$	1,899

Total accumulated comprehensive income at December 31, 2010	1,152			1,339		2,491
Less: Total accumulated comprehensive loss attributable to noncontrolling interest at December 31, 2010	666			—		666
Total accumulated comprehensive income attributable to SEI Investments Company at December 31, 2010	$	1,818		$	1,339	$	3,157

Total comprehensive loss	(3,195		)	1,235		(1,960		)
Less: Total comprehensive loss attributable to noncontrolling interest	703			—		703
Total comprehensive loss attributable to SEI Investments Company	$	(2,492	)	$	1,235	$	(1,257	)

Total accumulated comprehensive income at December 31, 2011	(2,043		)	2,574		531
Less: Total accumulated comprehensive loss attributable to noncontrolling interest at December 31, 2011	1,369			—		1,369
Total accumulated comprehensive income attributable to SEI Investments Company at December 31, 2011	$	(674	)	$	2,574	$	1,900

Total comprehensive income	5,904			255		6,159
Less: Total comprehensive income attributable to noncontrolling interest	(1,820		)	—		(1,820		)
Total comprehensive income attributable to SEI Investments Company	$	4,084		$	255	$	4,339

Total accumulated comprehensive income at December 31, 2012	3,861			2,829		6,690
Less: Total accumulated comprehensive income attributable to noncontrolling interest at December 31, 2012	(451		)	—		(451		)
Total accumulated comprehensive income attributable to SEI Investments Company at December 31, 2012	$	3,410		$	2,829	$	6,239

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2012

Income Tax Disclosure [Abstract]

Schedule Of Federal And State And Foreign Income Tax Provision

The federal and state and foreign income tax provision is summarized as follows:



Year Ended December 31,	2012			2011			2010
Current
Federal	$	112,247		$	99,448		$	116,388
State	5,284			7,067			8,698
Foreign	4,511			4,603			3,365
	122,042			111,118			128,451
Deferred, including current deferred
Federal	(2,708		)	(2,317		)	6,085
State	(2,199		)	2,477			1,509
Foreign	3,970			6			—
	(937		)	166			7,594
Income taxes attributable to the Noncontrolling interest	357			553			416
Total income taxes	$	121,462		$	111,837		$	136,461

Components Of Net Income Before Income Taxes

The components of Net income before income taxes are summarized as follows:



Year Ended December 31,	2012		2011		2010
Domestic	$	319,907	$	309,391	$	360,937
Foreign	8,046		6,852		6,795
	$	327,953	$	316,243	$	367,732

Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate

The effective income tax rate differs from the federal income tax statutory rate due to the following:



Year Ended December 31,	2012		2011		2010
Statutory rate	35.0	%	35.0	%	35.0	%
State taxes, net of Federal tax benefit	1.0		2.0		2.0
Foreign tax expense and tax rate differential	1.6		0.6		0.4
Research and development tax credit	—		(0.7	)	(0.5	)
Domestic Production Activities Deduction	(0.6	)	(0.7	)	—
Valuation allowance on PA loss carryforwards	(0.3	)	—		—
Domestic Production Activities Deduction, prior years, net	—		(1.5	)	—
Net change in uncertain tax positions (1)	0.5		0.4		0.2
Other, net	(0.3	)	0.1		(0.1	)
	36.9	%	35.2	%	37.0	%

Schedule of Deferred Tax Assets and Liabilities

The net deferred income tax liability is comprised of:



Year Ended December 31,	2012			2011
Current deferred income taxes:
Gross assets	$	2,012		$	1,151
Gross liabilities	—			(1		)
	2,012			1,150
Valuation allowance	—			—
	2,012			1,150
Long-term deferred income taxes:
Gross assets	63,129			63,374
Gross liabilities	(149,708		)	(148,540		)
	(86,579		)	(85,166		)
Valuation allowance	(6,879		)	(8,585		)
	(93,458		)	(93,751		)
Net deferred income tax liability	$	(91,446	)	$	(92,601	)

Schedule of Tax Effect of Tempoarary Differences Representing Net Deferred Tax Asset or Liability [Table Text Block]

The tax effect of significant temporary differences representing deferred tax liabilities is:



Year Ended December 31,	2012			2011
Difference in financial reporting and income tax depreciation methods	$	(10,104	)	$	(13,600	)
Reserves not currently deductible	325			374
Capitalized software currently deductible for tax purposes, net of amortization	(137,467		)	(139,455		)
State deferred income taxes	5,943			6,717
Revenue and expense recognized in different periods for financial reporting and income tax purposes	4,397			3,149
Unrealized holding gain on investments	(1,428		)	(927		)
Stock-based compensation expense	42,133			43,879
State net operating loss carryforward	13,883			14,485
Valuation allowance on deferred tax assets	(6,879		)	(8,585		)
Federal benefit of state tax deduction for uncertain tax positions	2,359			1,725
Foreign currency exchange	(39		)	(363		)
Foreign deferred including taxes on cumulative undistributed earnings of SEI AK	(4,569		)	—
Net deferred income tax liability	$	(91,446	)	$	(92,601	)

Schedule of Unrecognized Tax Benefits Roll Forward

A reconciliation of the beginning and ending amount of unrecognized tax benefit is as follows:



	2012			2011			2010
Balance as of January 1	$	9,410		$	5,723		$	4,989
Tax positions related to current year:
Gross additions	2,196			2,392			1,372
Gross reductions	—			—			—
	2,196			2,392			1,372
Tax positions related to prior years:
Gross additions	1,990			1,992			—
Gross reductions	—			—			(104		)
	1,990			1,992			(104		)
Settlements	(99		)	—			(102		)
Lapses on statute of limitations	(1,944		)	(697		)	(432		)
Balance as of December 31	$	11,553		$	9,410		$	5,723

Business Segment Information (Tables)

12 Months Ended

Dec. 31, 2012

Segment Reporting [Abstract]

Financial Information About Business Segments

The following tables highlight certain financial information about each of the Company’s business segments for the years ended December 31, 2012, 2011, and 2010:



	Private Banks			Investment Advisors			Institutional Investors			Investment Managers			Investments In New Businesses			Total
	For the Year Ended December 31, 2012
Revenues	$	364,788		$	202,703		$	227,889		$	193,484		$	3,658		$	992,522
Expenses	357,001			120,146			116,546			127,525			14,954			736,172
Operating profit (loss)	$	7,787		$	82,557		$	111,343		$	65,959		$	(11,296	)	$	256,350
Profit margin	2		%	41		%	49		%	34		%	N/A			26		%



	Private Banks			Investment Advisors			Institutional Investors			Investment Managers			Investments In New Businesses			Total
	For the Year Ended December 31, 2011
Revenues	$	348,122		$	189,780		$	210,027		$	177,975		$	3,823		$	929,727
Expenses	339,339			110,438			106,585			115,963			11,559			683,884
Operating profit (loss)	$	8,783		$	79,342		$	103,442		$	62,012		$	(7,736	)	$	245,843
Profit margin	3		%	42		%	49		%	35		%	N/A			26		%



	Private Banks			Investment Advisors			Institutional Investors			Investment Managers			Investments In New Businesses			Total
	For the Year Ended December 31, 2010
Revenues	$	346,668		$	183,378		$	206,531		$	160,159		$	4,099		$	900,835
Expenses	310,633			110,388			106,934			103,421			12,676			644,052
Operating profit (loss)	$	36,035		$	72,990		$	99,597		$	56,738		$	(8,577	)	$	256,783
Profit margin	10		%	40		%	48		%	35		%	N/A			29		%

Reconciliation Of Total Operating Profit Reported For Business Segments To Income From Operations In Consolidated Statements Of Operations



Year Ended December 31,	2012			2011			2010
Total operating profit from segments above	$	256,350		$	245,843		$	256,783
Corporate overhead expenses	(45,759		)	(43,398		)	(40,715		)
Noncontrolling interest reflected in segments	975			1,620			1,465
Income from operations	$	211,566		$	204,065		$	217,533

Additional Information Pertaining To Business Segments

The following tables provide additional information for the years ended December 31, 2012, 2011, and 2010 pertaining to our business segments:



	Capital Expenditures						Depreciation
Year Ended December 31,	2012		2011		2010		2012		2011		2010
Private Banks	$	32,509	$	35,045	$	32,982	$	15,226	$	15,648	$	15,704
Investment Advisors	11,193		11,933		11,691		1,981		2,251		2,384
Institutional Investors	2,781		2,059		2,601		1,012		1,079		1,170
Investment Managers	5,494		3,081		3,659		1,914		1,809		1,891
Investments in New Businesses	632		577		608		1,716		114		148
Total from business segments	$	52,609	$	52,695	$	51,541	$	21,849	$	20,901	$	21,297
Corporate Overhead	1,465		530		799		737		570		605
	$	54,074	$	53,225	$	52,340	$	22,586	$	21,471	$	21,902



	Amortization
Year Ended December 31,	2012		2011		2010
Private Banks	$	22,218	$	18,081	$	15,100
Investment Advisors	7,167		6,201		5,467
Institutional Investors	1,208		864		1,213
Investment Managers	804		580		820
Investments in New Businesses	1,249		433		477
Total from business segments	$	32,646	$	26,159	$	23,077
Corporate Overhead	612		1,129		971
	$	33,258	$	27,288	$	24,048



	Total Assets
	2012		2011
Private Banks	$	481,602	$	457,333
Investment Advisors	120,255		119,053
Institutional Investors	99,461		80,133
Investment Managers	118,221		95,760
Investments in New Businesses	5,846		5,962
Total from business segments	$	825,385	$	758,241
Corporate Overhead (1)	484,439		536,318
	$	1,309,824	$	1,294,559

Revenues And Assets Based On Location

The following table presents revenues based on the location of the use of the products or services:



For the Year Ended December 31,	2012		2011		2010
United States	$	843,407	$	785,506	$	767,068
International operations	149,115		144,221		133,767
	$	992,522	$	929,727	$	900,835

The following table presents assets based on their location:



	2012		2011
United States	$	1,066,451	$	1,098,643
International operations	243,373		195,916
	$	1,309,824	$	1,294,559

- Definition

Tabular disclosure of all significant reconciling items in the reconciliation of total profit or loss from reportable segments, to the entity's consolidated income before income taxes, extraordinary items, and discontinued operations.

+ References+ Details

- Definition

Tabular disclosure of each significant reconciling item, other than profit (loss), revenues, or assets, in the reconciliation of totals of such items in reportable segments to the entity's corresponding consolidated amount.

+ References+ Details

- Definition

Tabular disclosure of information concerning material long-lived assets (excluding financial instruments, customer relationships with financial institutions, mortgage and other servicing rights, deferred policy acquisition costs, and deferred taxes assets) located in identified geographic areas and/or the amount of revenue from external customers attributed to that country from which revenue is material. An entity may also provide subtotals of geographic information about groups of countries.

+ References+ Details

- Definition

Tabular disclosure of the profit or loss and total assets for each reportable segment. An entity discloses certain information on each reportable segment if the amounts (a) are included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) are otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss.

+ References+ Details

Quarterly Financial Data (Tables)

12 Months Ended

Dec. 31, 2012

Quarterly Financial Data [Abstract]

Quarterly Financial Information

Quarterly Financial Data (Unaudited)



	For the Three Months Ended
2012	March 31			June 30			Sept. 30			Dec. 31
Revenues	$	237,898		$	241,237		$	251,752		$	261,635
Income before income taxes	$	79,950		$	78,501		$	83,501		$	87,544
Net income attributable to SEI	$	49,965		$	49,555		$	50,743		$	56,585
Basic earnings per share	$	0.28		$	0.28		$	0.29		$	0.33
Diluted earnings per share	$	0.28		$	0.28		$	0.29		$	0.32

Effective income tax rate	37.2		%	36.6		%	39.0		%	35.0		%

Total SIV-related gains	$	2,882		$	1,072		$	3,389		$	5,897
Diluted earnings per share (1)	$	0.01		$	—		$	0.01		$	0.02

(1) Attributable to SIV-related gains.



	For the Three Months Ended
2011	March 31			June 30			Sept. 30			Dec. 31
Revenues	$	232,493		$	237,760		$	233,227		$	226,247
Income before income taxes	$	92,164		$	82,820		$	74,900		$	68,603
Net income attributable to SEI	$	57,728		$	53,603		$	49,232		$	44,396
Basic earnings per share	$	0.31		$	0.29		$	0.27		$	0.25
Diluted earnings per share	$	0.31		$	0.29		$	0.27		$	0.25

Effective income tax rate	37.1		%	34.7		%	33.8		%	34.7		%

Total SIV-related gains (losses)	$	6,864		$	(1,944	)	$	(792	)	$	(738	)
Diluted earnings per share (2)	$	0.02		$	0.01		$	—		$	—

(2) Attributable to SIV-related gains (losses).

Schedule II - Valuation And Qualifying Accounts And Reserves Valuation And Qualifying Accounts And Reserves (Tables)

12 Months Ended

Dec. 31, 2012

Valuation and Qualifying Accounts [Abstract]

Valuation And Qualifying Accounts



Schedule II - Valuation and Qualifying Accounts and Reserves								SEI Investments Company and Subsidiaries

Year Ended December 31,			Additions
Description	Balance at Beginning of Year		Charged to Costs and Expenses			Charged to Other Accounts		(Deductions)			Balance at End of Year
Allowance for doubtful accounts:
2012	$	924	$	—		$	—	$	(119	)	$	805
2011	1,195		—			—		(271		)	924
2010	3,348		—			—		(2,153		)	1,195
Deferred income tax valuation allowance:
2012	$	8,585	$	(1,706	)	$	—	$	—		$	6,879
2011	9,008		(423		)	—		—			8,585
2010	6,217		1,443			1,348		—			9,008

- Definition

Tabular disclosure of valuation allowances to reduce deferred tax assets to net realizable value, including identification of the deferred tax asset more likely than not will not be fully realized and the corresponding amount of the valuation allowance.

+ References+ Details

Summary Of Significant Accounting Policies (Narrative) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended				3 Months Ended	12 Months Ended												12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2012 Global Wealth Platform [Member]	Dec. 31, 2012 Global Wealth Platform [Member]	Dec. 31, 2012 Minimum [Member]	Dec. 31, 2012 Maximum [Member]	Dec. 31, 2012 Noncontrolling Interest [Member]	Dec. 31, 2012 Equity Method Investee [Member] Minimum [Member]	Dec. 31, 2012 Equity Method Investee [Member] Maximum [Member]	Dec. 31, 2012 SEI-Sponsored Open-Ended Money Market Mutual Funds [Member]	Dec. 31, 2011 SEI-Sponsored Open-Ended Money Market Mutual Funds [Member]	Dec. 31, 2012 SEI Investments (Europe) Limited [Member]	Dec. 31, 2011 SEI Investments (Europe) Limited [Member]	Dec. 31, 2012 SEI Investments Distribution Co. (SIDCO) [Member]	Dec. 31, 2011 SEI Investments Distribution Co. (SIDCO) [Member]	Dec. 31, 2012 Building and Building Improvements [Member] Minimum [Member]	Dec. 31, 2012 Building and Building Improvements [Member] Maximum [Member]	Dec. 31, 2012 Computer Equipment [Member] Minimum [Member]	Dec. 31, 2012 Computer Equipment [Member] Maximum [Member]	Dec. 31, 2012 Furniture and Fixtures [Member] Minimum [Member]	Dec. 31, 2012 Furniture and Fixtures [Member] Maximum [Member]
Noncontrolling Interest, Ownership Percentage by Parent									100.00%
Equity Method Investment, Ownership Percentage								50.00%		20.00%	50.00%
Cash and cash equivalents	$ 452,247	$ 420,986	$ 496,292	$ 590,877								$ 247,314	$ 281,760
Restricted cash														5,000	5,000	1,000	1,000
Property, Plant and Equipment, Useful Life																		25 years	39 years	3 years	5 years	3 years	5 years
Net book value of GWP					304,271	304,271
Capitalized software, accumulated amortization	149,747	117,100			119,939	119,939
Capitalized software development costs in-progress associated with future releases					2,795	2,795
Payments to Acquire Software	31,004	40,954	38,729
Software Development Cost Useful Life						15 years	3 years	15 years
Capitalized Software Weighted Average Remaining Life	9 years 6 months				9 years 6 months	9 years 6 months
Amortization expense related to capitalized software	32,647	26,153	23,053
Accelerated amortization for GWP abandoned components					2,661
Capitalized Computer Software, Impairments	0	0
Foreign Currency Transaction Gain (Loss), Realized	$ 0	$ 0	$ 0
Anti-dilutive employee stock options	13,202,000	15,914,000	13,181,000
Antidilutive Securities Excluded from Computation of Net Income, Per Outstanding Unit, Amount	$ 24.76	$ 23.07	$ 23.79

Summary Of Significant Accounting Policies (Calculation Of Basic And Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Accounting Policies [Abstract]
Basic earnings per common share, Income (Numerator)	$ 56,585	$ 50,743	$ 49,555	$ 49,965	$ 44,396	$ 49,232	$ 53,603	$ 57,728	$ 206,848	$ 204,959	$ 231,687
Basic earnings per common share, shares									174,295	182,547	188,468
Basic earnings per common share	$ 0.33	$ 0.29	$ 0.28	$ 0.28	$ 0.25	$ 0.27	$ 0.29	$ 0.31	$ 1.19	$ 1.12	$ 1.23
Dilutive effect of stock options, Income (Numerator)									0	0	0
Dilutive effect of stock options, Shares (Denominator)									1,577	1,580	1,853
Diluted earnings per common share, Income (Numerator)									$ 206,848	$ 204,959	$ 231,687
Diluted earnings per common share, shares									175,872	184,127	190,321
Diluted earnings per common share	$ 0.32	$ 0.29	$ 0.28	$ 0.28	$ 0.25	$ 0.27	$ 0.29	$ 0.31	$ 1.18	$ 1.11	$ 1.22

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 128

-Paragraph 36, 37, 38

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

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-Number 210

-Section 04

-Paragraph 18

-Article 7

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 20

-Article 5

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-Number 210

-Section 04

-Paragraph 21

-Article 9

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-Paragraph 1

-Subparagraph (SX 210.9-04.23)

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+ Details

- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 130

-Paragraph 10, 15

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 19

-Article 5

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 20

-Article 9

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-Paragraph 28, 29, 30

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-Glossary Other Comprehensive Income

-URI http://asc.fasb.org/extlink&oid=6519514

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-Name Accounting Standards Codification

-Glossary Net Income

-URI http://asc.fasb.org/extlink&oid=6518256

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-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph a

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-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph A7

-Appendix A

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-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph d

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-Name Emerging Issues Task Force (EITF)

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Reference 16: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.18)

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

+ Details

- Definition

The sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation.

+ References+ Details

- Definition

This element represents the weighted average total number of shares issued throughout the period including the first (beginning balance outstanding) and last (ending balance outstanding) day of the period before considering any reductions (for instance, shares held in treasury) to arrive at the weighted average number of shares outstanding. Weighted average relates to the portion of time within a reporting period that common shares have been issued and outstanding to the total time in that period. Such concept is used in determining the weighted average number of shares outstanding for purposes of calculating earnings per share (basic).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 128

-Paragraph 40

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 45

-Paragraph 13

-URI http://asc.fasb.org/extlink&oid=7655603&loc=d3e2646-109256

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-Name Statement of Financial Accounting Standard (FAS)

-Number 128

-Paragraph 10

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 45

-Paragraph 10

-URI http://asc.fasb.org/extlink&oid=7655603&loc=d3e1448-109256

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 128

-Paragraph 8

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Investment In Unconsolidated Affiliates (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	1 Months Ended	12 Months Ended							1 Months Ended	12 Months Ended					12 Months Ended			12 Months Ended			12 Months Ended			12 Months Ended				12 Months Ended
	Jan. 31, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 LSV Employee Group II [Member]	Dec. 31, 2011 LSV Employee Group II [Member]	Jan. 31, 2013 LSV Employee Group II [Member]	Apr. 11, 2011 LSV Employee Group II [Member]	Jan. 31, 2013 LSV Employee Group III [Member]	Dec. 31, 2012 LSV Employee Group III [Member]	Oct. 02, 2012 LSV Employee Group III [Member]	Dec. 31, 2012 Maximum [Member]	Dec. 31, 2012 Financial Guarantee [Member] LSV Employee Group [Member]	Jan. 24, 2006 Financial Guarantee [Member] LSV Employee Group [Member]	Dec. 31, 2012 Financial Guarantee [Member] LSV Employee Group II [Member]	Jan. 31, 2013 Financial Guarantee [Member] LSV Employee Group II [Member]	Apr. 11, 2011 Financial Guarantee [Member] LSV Employee Group II [Member]	Dec. 31, 2012 Financial Guarantee [Member] LSV Employee Group III [Member]	Jan. 31, 2013 Financial Guarantee [Member] LSV Employee Group III [Member]	Oct. 02, 2012 Financial Guarantee [Member] LSV Employee Group III [Member]	Dec. 31, 2012 Financial Guarantee [Member] L S V Asset Management [Member]	Jan. 31, 2013 Financial Guarantee [Member] L S V Asset Management [Member]	Oct. 02, 2012 Financial Guarantee [Member] L S V Asset Management [Member]	Dec. 31, 2012 L S V Asset Management [Member]	Dec. 31, 2011 L S V Asset Management [Member]	Dec. 31, 2010 L S V Asset Management [Member]	Dec. 31, 2012 L S V Asset Management [Member]	Dec. 31, 2012 Gao Fu [Member]
Investments in and Advances to Affiliates [Line Items]
Equity method investment, ownership percentage												50.00%												39.80%	41.20%
Total investment in equity method investee																								$ 68,716				$ 8,682
Investment in equity method investee in excess of the underlying equity in net assets																											3,280
Goodwill																								3,062
Company's share in the earnings of equity method investee		98,671	105,818	99,457																				99,989	105,818	99,457		(1,318)
Partnership distribution payments received from LSV	21,242	92,227	109,273	93,302
Guarantor Obligations, Maximum Exposure, Undiscounted														82,800			3,655		45,000	45,000		22,563	24,930
Guarantor Obligations, Current Carrying Value													0			0			0
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned								4,300			77,700
Guarantor Obligations, Term															4			5			3
Variable interest entity, principal payment					1,031	458			2,367	0
Loans Payable					$ 2,166		$ 1,923				$ 69,930

Investment In Unconsolidated Affiliates Investment In Unconsolidated Affiliates (Condensed Statements of Operations of LSV) (Details) (LSV Asset Management [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
LSV Asset Management [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Summarized Financial Information, Revenue	$ 296,261	$ 296,397	$ 273,381
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	$ 250,165	$ 257,519	$ 239,981

- Definition

The amount of net income (loss) reported by an equity method investment of the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 28

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14064-108612

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(g))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33912-111571

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph g

-Subparagraph 1, 2

-Article 4

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph w

-Article 1

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 18

-Paragraph 20

-Subparagraph d

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Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 159

-Paragraph 18

-Subparagraph f

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph bb

-Article 1

+ Details

Investment In Unconsolidated Affiliates Investment In Unconsolidated Affiliates (Condensed Balance Sheets of LSV) (Details) (LSV Asset Management [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
LSV Asset Management [Member]
Equity Method Investment, Summarized Financial Information, Current Assets	$ 145,367	$ 136,601
Equity Method Investment, Summarized Financial Information, Noncurrent Assets	3,120	3,880
Equity Method Investment, Summarized Financial Information, Assets	148,487	140,481
Equity Method Investment, Summarized Financial Information, Current Liabilities	17,869	13,933
Equity Method Investment Summarized Financial Information, Equity	130,618	126,548
Equity Method Investment, Summarized Financial Information, Liabilities and Equity	$ 148,487	$ 140,481

- Definition

The amount of assets reported by an equity method investment of the entity.

+ References

+ Details

- Definition

The amount of current assets reported by an equity method investment of the entity.

+ References

+ Details

- Definition

The amount of current liabilities reported by an equity method investment of the entity.

+ References

+ Details

- Definition

Amount of equity, including noncontrolling interest, reported by an equity method investment of the entity.

+ References+ Details

- Definition

The amount of liabilities and equity reported by an equity method investment of the entity.

+ References

+ Details

- Definition

The amount of noncurrent assets reported by an equity method investment of the entity.

+ References

+ Details

Composition Of Certain Financial Statement Captions (Receivables) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Items Included in Consolidated Statement of Financial Condition [Abstract]
Billed Contracts Receivable	$ 46,650	$ 37,822
Unbilled Contracts Receivable	116,019	92,916
Other receivables	9,870	12,295
Gross receivables	172,539	143,033
Less: Allowance for doubtful accounts	(805)	(924)
Receivables, net	$ 171,734	$ 142,109

- Definition

Unbilled amounts due for services rendered or to be rendered, actions taken or to be taken, or a promise to refrain from taking certain actions in accordance with the terms of a legally binding agreement between the entity and, at a minimum, one other party. An example would be amounts associated with contracts or programs where the recognized revenue for performance thereunder exceeds the amounts billed under the terms thereof as of the date of the balance sheet.

+ References+ Details

Composition Of Certain Financial Statement Captions (Property And Equipment) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Items Included in Consolidated Statement of Financial Condition [Abstract]
Buildings	$ 137,751	$ 136,949
Equipment	66,167	64,256
Land	9,929	9,929
Purchased software	91,468	77,971
Furniture and fixtures	18,535	17,999
Leasehold improvements	5,037	4,558
Construction in progress	112	339
Property and Equipment, gross	328,999	312,001
Less: Accumulated depreciation	(201,418)	(182,453)
Property and Equipment, net	127,581	129,548
Depreciation expense	$ 22,586	$ 21,471	$ 21,902

Composition Of Certain Financial Statement Captions Composition Of Certain Financial Statement Captions (Other Assets) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Other Assets [Abstract]
Other Deferred Cost, Amortization Expense	$ 611	$ 1,135	$ 995
Gain (Loss) on Sale of Other Assets			$ 3,072

Composition Of Certain Financial Statement Captions (Accrued Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Items Included in Consolidated Statement of Financial Condition [Abstract]
Accrued employee compensation	$ 63,996	$ 48,112
Accrued employee benefits and other personnel	7,299	5,408
Accrued consulting, outsourcing and professional fees	16,676	17,477
Accrued brokerage fees	5,733	8,665
Accrued sub-advisory, distribution and other asset management fees	17,548	17,091
Accrued dividend payable	0	26,518
Other accrued liabilities	27,053	23,773
Total accrued liabilities	$ 138,305	$ 147,044

- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and payable for professional fees, such as for legal and accounting services received. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6361293&loc=d3e6935-107765

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Current Liabilities

-URI http://asc.fasb.org/extlink&oid=6509677

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 43

-Section A

-Paragraph 7

-Chapter 3

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.20)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=6361293&loc=d3e6911-107765

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-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 43

-Section A

-Paragraph 8

-Chapter 3

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

- Definition

Carrying value as of the balance sheet date of the obligations incurred through that date and payable for employees' services provided. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

+ Details

- Definition

Carrying value as of the balance sheet date of dividends declared but unpaid on equity securities issued by the entity and outstanding. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References+ Details

- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and payable arising from transactions not otherwise specified in the taxonomy. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References+ Details

Fair Value Measurements (Narrative) (Details) (USD $)	12 Months Ended
Fair Value Measurements (Narrative) (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net	$ 0	$ 0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial liabilities	0	0
Gryphon SIV [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading Securities, Realized Gain (Loss)	$ 5,322,000

Fair Value Measurements (Fair Value Of Certain Financial Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity available-for-sale securities	$ 15,926	$ 8,010
Fixed income available-for-sale securities	59,943	74,998
Fixed income securities owned	20,088	20,949
Trading securities	5,909	56,325
Assets, fair value	101,866	160,282
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity available-for-sale securities	15,926	8,010
Fixed income available-for-sale securities	0	0
Fixed income securities owned	0	0
Trading securities	4,706	3,702
Assets, fair value	20,632	11,712
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity available-for-sale securities	0	0
Fixed income available-for-sale securities	59,943	74,998
Fixed income securities owned	20,088	20,949
Trading securities	0	0
Assets, fair value	80,031	95,947
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity available-for-sale securities	0	0
Fixed income available-for-sale securities	0	0
Fixed income securities owned	0	0
Trading securities	1,203	52,623
Assets, fair value	$ 1,203	$ 52,623

- Definition

Amount of debt securities categorized neither as held-to-maturity nor trading.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7534914&loc=d3e22054-111558

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 12

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

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-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 16

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

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-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 13

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

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-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15D

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

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-Paragraph 15C

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Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 320

-Section 50

-Paragraph 2

-Subparagraph (b)-(g)

-URI http://asc.fasb.org/extlink&oid=6957658&loc=d3e62557-112803

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-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 137

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

- Definition

Amount of equity securities categorized neither as held-to-maturity nor as trading.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

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-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 12

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 16

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

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Reference 5: http://www.xbrl.org/2003/role/presentationRef

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-Name Statement of Financial Accounting Standard (FAS)

-Number 133

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

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-Name Statement of Financial Accounting Standard (FAS)

-Number 115

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 3

-Subparagraph c

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 320

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6957658&loc=d3e62557-112803

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-Publisher FASB

-Name Emerging Issues Task Force (EITF)

-Number 86-40

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

- Definition

Total common and preferred stock (which is not mandatorily redeemable, redeemable at the option of the holder, or in any other way classified as liability) equity securities that are bought and held principally for the purpose of selling them in the near term (thus held for only a short period of time) or for equity securities formerly categorized as available-for-sale or held-to-maturity which the entity held as of the date it opted to account for such securities at fair value. An enterprise may also categorize such a security as trading without the intent to sell it in the near term assuming the decision to categorize the security as trading occurred at acquisition.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 13

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26626-111562

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 159

-Paragraph 29

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 12

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Implementation Guide (Q and A)

-Number FAS115

-Paragraph 35

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.4)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Trading Securities

-URI http://asc.fasb.org/extlink&oid=6526789

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.(a),1(b))

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

Fair Value Measurements (Reconciliation For All Assets And Liabilities Of The Company Measured At Fair Value On A Recurring Basis Using Significant Unobservable Inputs (Level 3)) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance, January 1	$ 52,623	$ 100,645
Purchases	13	1,215
Issuances	0	0
Principal prepayments and settlements	(10,728)	(17,921)
Sales	(53,920)	(34,706)
Total gains or (losses) (realized/unrealized), Included in earnings	13,215	3,390
Total gains or (losses) (realized/unrealized), Included in other comprehensive income	0	0
Transfers in and out of Level 3	0	0
Ending balance	$ 1,203	$ 52,623

Marketable Securities (Narrative) (Details) (USD $)	12 Months Ended				3 Months Ended		12 Months Ended		3 Months Ended								12 Months Ended
Marketable Securities (Narrative) (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2012 SEI Private Trust Company [Member] Minimum [Member]	Dec. 31, 2012 SEI Private Trust Company [Member] Maximum [Member]	Dec. 31, 2012 U.S. Government Agency And Commercial Paper Securities [Member]	Dec. 31, 2011 U.S. Government Agency And Commercial Paper Securities [Member]	Dec. 31, 2012 SIV Securities [Member]	Sep. 30, 2012 SIV Securities [Member]	Jun. 30, 2012 SIV Securities [Member]	Mar. 31, 2012 SIV Securities [Member]	Dec. 31, 2011 SIV Securities [Member]	Sep. 30, 2011 SIV Securities [Member]	Jun. 30, 2011 SIV Securities [Member]	Mar. 31, 2011 SIV Securities [Member]	Dec. 31, 2012 SIV Securities [Member]	Dec. 31, 2011 SIV Securities [Member]	Dec. 31, 2010 SIV Securities [Member]	Dec. 31, 2012 Gryphon SIV [Member]	Dec. 31, 2011 Stanfield Victoria SIV [Member]	Dec. 31, 2012 LSV-Sponsored Mutual Funds [Member]	Dec. 31, 2011 LSV-Sponsored Mutual Funds [Member]
Schedule of Investments [Line Items]
Net unrealized holding gains	$ 2,829,000	$ 2,574,000	$ 1,339,000	$ 960,000
Unrealized holding gains during the period, income tax expense	1,554,000	1,518,000
Available-for-sale Securities, Gross Realized Gain (Loss)	0	0	0
Available-for-sale Securities, Debt Maturities, Date					Dec. 15, 2020	Nov. 15, 2041
Net gains from SIV securities																	13,240,000	3,390,000	44,247,000
Gains from cash payments received from SIV securities																	6,776,000	10,614,000	27,510,000
Gains or losses from increase/decrease in fair value of SIV securities																	1,142,000	(7,224,000)	16,460,000
Trading Securities, Realized Gain (Loss)									5,897,000	3,389,000	1,072,000	2,882,000	(738,000)	(792,000)	(1,944,000)	6,864,000				5,322,000	0	1,004,000	0
Securities owned	20,088,000	20,949,000					20,088,000	20,949,000
Realized Investment Gains (Losses)							$ 0	$ 0

Marketable Securities (Investments Available For Sale) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Investment Available for Sale, Cost Amount	$ 71,486	$ 78,916
Investment Available for Sale, Gross Unrealized Gains	4,396	4,452
Investment Available for Sale, Gross Unrealized Losses	(13)	(360)
Investment Available for Sale, Fair Value	75,869	83,008
SEI-Sponsored Mutual Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment Available for Sale, Cost Amount	12,953	8,243
Investment Available for Sale, Gross Unrealized Gains	376	48
Investment Available for Sale, Gross Unrealized Losses	(13)	(360)
Investment Available for Sale, Fair Value	13,316	7,931
Equity Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment Available for Sale, Cost Amount	2,610	69
Investment Available for Sale, Gross Unrealized Gains	0	10
Investment Available for Sale, Gross Unrealized Losses	0	0
Investment Available for Sale, Fair Value	2,610	79
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment Available for Sale, Cost Amount	55,923	70,604
Investment Available for Sale, Gross Unrealized Gains	4,020	4,394
Investment Available for Sale, Gross Unrealized Losses	0	0
Investment Available for Sale, Fair Value	$ 59,943	$ 74,998

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References+ Details

- Definition

This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details

- Definition

Investments in debt and equity securities which are categorized neither as held-to-maturity nor trading and which are intended to be sold or mature more than one year from the balance sheet date or operating cycle, if longer. Such securities are reported at fair value; unrealized gains (losses) related to Available-for-sale Securities are excluded from earnings and reported in a separate component of shareholders' equity (other comprehensive income), unless the Available-for-sale security is designated as a hedge or is determined to have had an other than temporary decline in fair value below its amortized cost basis. All or a portion of the unrealized holding gain (loss) of an Available-for-sale security that is designated as being hedged in a fair value hedge is recognized in earnings during the period of the hedge, as are other than temporary declines in fair value below the cost basis for investments in equity securities and debt securities that an entity intends to sell or it is more likely than not that it will be required to sell before the recovery of its amortized cost basis. Other than temporary declines in fair value below the cost basis for debt securities categorized as Available-for-sale that an entity does not intend to sell and for which it is not more likely than not that the entity will be required to sell before the recovery of its amortized cost basis are bifurcated into credit losses and losses related to all other factors. Other than temporary declines in fair value below cost basis related to credit losses are recognized in earnings, and losses related to all other factors are recognized in other comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 12

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15D

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26626-111562

Reference 4: http://www.xbrl.org/2003/role/presentationRef

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-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15E

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15C

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Available-for-Sale Securities

-URI http://asc.fasb.org/extlink&oid=6505594

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 17

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Marketable Securities (Trading Securities) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities, Cost	$ 3,277	$ 149,627
Trading Securities, Gross Unrealized Gains	2,657	1,653
Trading Securities, Gross Unrealized Losses	(25)	(94,955)
Trading Securities, Fair Value	5,909	56,325
SIV Securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities, Cost		146,363
Trading Securities, Gross Unrealized Gains		0
Trading Securities, Gross Unrealized Losses		(94,955)
Trading Securities, Fair Value		51,408
LSV-Sponsored Mutual Funds [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities, Cost	2,049	2,049
Trading Securities, Gross Unrealized Gains	2,657	1,653
Trading Securities, Gross Unrealized Losses	0	0
Trading Securities, Fair Value	4,706	3,702
Other Investments [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Trading Securities, Cost	1,228	1,215
Trading Securities, Gross Unrealized Gains	0	0
Trading Securities, Gross Unrealized Losses	(25)	0
Trading Securities, Fair Value	$ 1,203	$ 1,215

- Definition

The increase (decrease) resulting in a gain from the difference between the fair value and the carrying value, or in the comparative fair values, of trading securities held at each balance sheet date, that was included in earnings for the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 13

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 12

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.7(c))

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 21

-Subparagraph e

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27357-111563

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 35

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=16383099&loc=d3e24584-111560

+ Details

- Definition

The increase (decrease) resulting in a loss from the difference between the fair value and the carrying value, or in the comparative fair values, of trading securities held at each balance sheet date, that was included in earnings for the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 13

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 12

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.7(c))

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Trading Securities

-URI http://asc.fasb.org/extlink&oid=6526789

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 21

-Subparagraph e

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 9

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 35

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=16383099&loc=d3e24584-111560

+ Details

Lines Of Credit (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended			3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Two Thousand Twelve Credit Facility [Member]	Dec. 31, 2012 Two Thousand Twelve Credit Facility [Member]	Dec. 31, 2011 Two Thousand Seven Credit Facility [Member]	Dec. 31, 2010 Two Thousand Seven Credit Facility [Member]	Dec. 31, 2012 Canadian Subsidiary Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit Agreement, years					5
Credit facility				$ 300,000	$ 300,000	$ 300,000		$ 2,000
Credit facility, expiration date				Feb. 02, 2017
Credit facility interest accrued, percentage above LIBOR				1.25%	1.25%	0.45%
Proceeds from Lines of Credit					0
Credit facility, commitment fee per annum on daily unused portion, percent				0.15%		0.09%
Aggregate amount that may increase under credit facility				100,000
Line of Credit Facility, Amount Outstanding				0	0	0		0
Line of Credit Facility, Decrease, Repayments	0	95,000	138,000			95,000	138,000
Line of Credit Facility, Interest Rate During Period						0.68%	0.77%
Interest Expense	$ 504	$ 585	$ 1,478		$ 471	$ 585	$ 1,478

Shareholders' Equity (Narrative) (Details) (USD $)	3 Months Ended	12 Months Ended			3 Months Ended			12 Months Ended		3 Months Ended
Shareholders' Equity (Narrative) (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Interim Cash Dividends [Member]	Jun. 30, 2012 Interim Cash Dividends [Member]	Dec. 31, 2012 Final Cash Dividends [Member]	Dec. 31, 2012 Minimum [Member]	Dec. 31, 2012 Maximum [Member]	Dec. 31, 2012 2007 Plan [Member] plans	Dec. 31, 2012 1998 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of active equity compensation plans										1
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	2,569,000	2,569,000								20,000,000	0
Vesting Rate When Specified Diluted Earnings Per Share Targets are Achieved										50.00%
Vesting Rate Higher Specified Diluted Earnings Per Share Targets are Achieved										50.00%
Stock options granted prior to 2006, vesting period, years		7 years
Option pricing model used to determine fair value of stock options		Black-Scholes
Weighted average fair value of stock options granted		$ 6.73	$ 5.70	$ 9.65
Change in management estimate of stock based compensation expense amortization				$ 11,663,000
Previously recognized stock-based compensation costs reversed				6,375,000
Unrecognized compensation cost	50,264,000	50,264,000		27,460,000
Total options that were exercisable	9,760,000	9,760,000	11,680,000	14,247,000
Expiration date for options outstanding								Dec. 16, 2013	Dec. 11, 2022
Options outstanding weighted average remaining contractual life, years		5 years 10 months 24 days
Total intrinsic value of options exercised		19,565,000	8,642,000
Aggregate intrinsic value of options exercisable	51,087,000	51,087,000
Total intrinsic value of options outstanding	64,823,000	64,823,000
Share Price	$ 23.34	$ 23.34
Employee stock purchase plan, employee eligible percentage on offerings of common stock		85.00%
Shares reserved under the plan	15,600,000	15,600,000
Issuance of common stock under the employee stock purchase plan, shares		11,580,000
Employee Stock Ownership Plan (ESOP), Compensation Expense		0	0	0
Remaining stock repurchase authorization amount	91,012,000
Rights received by common shareholder for each common share outstanding, rights	1	1
Series A Junior Participating Preferred stock, par value	$ 0.05	$ 0.05	$ 0.05
Securities and assets of equivalent value, purchase price, per unit	$ 150.00	$ 150.00
Number of days, rights become exercisable following public announcement		10
Acquiring Person, beneficial ownership of the outstanding common stock, minimum percentage	20.00%	20.00%
Holders, other than an acquiring person, right to purchase of common stock upon exercise of rights		twice
Common shares received by holders upon surrender of rights, percentage		50.00%
Rights non-voting, redeemable days		0 years 0 months 10 days
Right redeemable price, per right	$ 0.01	$ 0.01
Common Stock, Dividends, Per Share, Declared		$ 0.63	$ 0.27	$ 0.20	$ 0.16	$ 0.15	$ 0.32
Dividends, Common Stock		$ 108,817,000	$ 48,558,000	$ 37,513,000

Shareholders' Equity Shareholders' Equity (Assumptions Used In The Weighted Average Fair Value Of Stock Options Granted) (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Expected Term	6 years 9 months	7 years 7 months 24 days	7 years 5 months 12 days
Expected Volatility Rate	34.90%	40.43%	36.35%
Expected Dividend Rate	1.46%	1.90%	0.84%
Risk Free Interest Rate	1.03%	1.66%	3.01%

- Definition

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

+ References+ Details

Shareholders' Equity (Stock-Based Compensation Expense) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Stockholders' Equity Note [Abstract]
Stock-based compensation expense	$ 15,736	$ 14,112	$ 26,783
Less: Deferred tax benefit	(5,650)	(5,332)	(10,068)
Stock-based compensation expense, net of tax	$ 10,086	$ 8,780	$ 16,715

- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References+ Details

Shareholders' Equity (Stock Option Plans) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Balance	27,043,000	27,881,000	28,964,000
Balance, weighted avg. price	$ 20.06	$ 20.42	$ 20.09
Granted	2,470,000	2,534,000	2,883,000
Granted, weighted avg. price	$ 22.40	$ 15.77	$ 23.84
Exercised	3,136,000	1,364,000	1,633,000
Exercised, weighted avg. price	$ 15.19	$ 16.37	$ 16.04
Expired or canceled	767,000	2,008,000	2,333,000
Expired or canceled, weighted avg. price	$ 22.61	$ 22.07	$ 23.68
Balance	25,610,000	27,043,000	27,881,000
Balance, weighted avg. price	$ 20.81	$ 20.06	$ 20.42
Total options that were exercisable	9,760,000	11,680,000	14,247,000
Exercisable shares, weighted avg. price	$ 18.11
Available for future grant as of December 31, 2012	2,569,000

Shareholders' Equity (Stock Options Outstanding And Exercisable) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Shares	25,610,000	27,043,000	27,881,000	28,964,000
Weighted Average Exercise Price (Per Share)	$ 20.81	$ 20.06	$ 20.42	$ 20.09
Weighted Average Remaining Contractual Life (Years)	5 years 10 months 24 days
Number of Shares	9,760,000	11,680,000	14,247,000
Weighted Average Exercise Price (Per Share)	$ 18.11
First Range Of Exercise Prices [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Shares	5,065,000
Weighted Average Exercise Price (Per Share)	$ 14.69
Weighted Average Remaining Contractual Life (Years)	4 years 4 months 10 days
Number of Shares	3,153,000
Weighted Average Exercise Price (Per Share)	$ 14.73
Weighted Average Remaining Contractual Life (Years)	3 years 4 months 10 days
Lower range	$ 14.62
Upper range	$ 15.52
Second Range Of Exercise Prices [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Shares	5,999,000
Weighted Average Exercise Price (Per Share)	$ 16.87
Weighted Average Remaining Contractual Life (Years)	7 years 9 months 22 days
Number of Shares	1,647,000
Weighted Average Exercise Price (Per Share)	$ 17.63
Weighted Average Remaining Contractual Life (Years)	6 years 11 months 1 day
Lower range	$ 15.77
Upper range	$ 17.65
Third Range Of Exercise Prices [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Shares	4,981,000
Weighted Average Exercise Price (Per Share)	$ 20.37
Weighted Average Remaining Contractual Life (Years)	2 years 6 months 26 days
Number of Shares	4,945,000
Weighted Average Exercise Price (Per Share)	$ 20.39
Weighted Average Remaining Contractual Life (Years)	2 years 6 months 4 days
Lower range	$ 18.00
Upper range	$ 21.55
Fourth Range Of Exercise Prices [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Shares	5,143,000
Weighted Average Exercise Price (Per Share)	$ 23.19
Weighted Average Remaining Contractual Life (Years)	8 years 11 months 9 days
Number of Shares	0
Weighted Average Exercise Price (Per Share)	$ 0.00
Lower range	$ 22.45
Upper range	$ 23.86
Fifth Range Of Exercise Prices [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Shares	4,422,000
Weighted Average Exercise Price (Per Share)	$ 30.88
Weighted Average Remaining Contractual Life (Years)	4 years 5 months 16 days
Number of Shares	15,000
Weighted Average Exercise Price (Per Share)	$ 27.03
Weighted Average Remaining Contractual Life (Years)	4 years
Lower range	$ 27.03
Upper range	$ 32.49

- Definition

The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options.

+ References+ Details

Shareholders' Equity Shareholders' Equity (Common Stock Buyback) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Common Stock Buyback [Abstract]
Stock Repurchased and Retired During Period, Shares	7,528,000	11,109,000	5,814,000
Stock Repurchased During Period, Value	$ 155,264	$ 211,165	$ 120,982

- Definition

Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

+ References+ Details

Shareholders' Equity (Schedule Of Reconciliation Of Noncontrolling Interest On The Consolidated Balance Sheet) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Beginning balance	$ 16,143	$ 15,155	$ 121,895
Net income attributable to noncontrolling interest	1,186	1,691	1,633
Foreign currency translation adjustments	1,820	(703)	685
Ending balance	19,149	16,143	15,155
LSV Asset Management [Member]
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Noncontrolling Interest, Decrease from Deconsolidation	0	0	(65,522)
LSV Employee Group [Member]
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Noncontrolling Interest, Decrease from Deconsolidation	$ 0	$ 0	$ (43,536)

- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which is directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent (that is, noncontrolling interest, previously referred to as minority interest).

+ References+ Details

- Definition

Amount of Net Income (Loss) attributable to noncontrolling interest.

+ References+ Details

- Definition

Amount after tax and reclassification adjustments, resulting from the process of expressing in the reporting currency of the reporting entity those amounts that are denominated or measured in a different currency, and from transactions whose terms are denominated in a currency other than the entity's functional currency, which is attributable to noncontrolling interests.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph c(3)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 30

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 45

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=7656940&loc=SL4569643-111683

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 45

-Paragraph 19

-URI http://asc.fasb.org/extlink&oid=7656940&loc=SL4569616-111683

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 29

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (c)(3)

-URI http://asc.fasb.org/extlink&oid=18733093&loc=SL4573702-111684

+ Details

Accumulated Comprehensive Income (Loss) (Schedule Of Accumulated Other Comprehensive Income (Loss), Net Of Tax) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Accumulated other comprehensive income (loss), Foreign Currency Translation Adjustments	$ 3,410	$ (674)	$ 1,818	$ 298
Accumulated other comprehensive income (loss), Unrealized Holding Gains (Losses) on Investments	2,829	2,574	1,339	960
Accumulated Other Comprehensive Income (Loss)	6,239	1,900	3,157	1,258
Total comprehensive loss, Foreign Currency Translation Adjustments	5,904	(3,195)	2,205
Total comprehensive loss, Unrealized Holding Gains (Losses) on Investments	255	1,235	379
Other Comprehensive Income (Loss), Net of Tax	6,159	(1,960)	2,584
Total comprehensive loss attributable to noncontrolling interest, Foreign Currency Translation Adjustments	(1,820)	703	(685)
Total comprehensive income attributable to noncontrolling interest, Unrealized Holding Gains (Losses) on Investments	0	0	0
Total comprehensive loss attributable to noncontrolling interest	(1,820)	703	(685)
Total comprehensive income attributable to SEI Investments Company, Foreign Currency Translation Adjustments	4,084	(2,492)	1,520
Total comprehensive (loss) attributable to SEI Investments Company, Unrealized Holding Gains (Losses) on Investments	255	1,235	379
Total comprehensive income attributable to SEI Investments Company	4,339	(1,257)	1,899
SEI Investments Company [Member]
Accumulated other comprehensive income (loss), Foreign Currency Translation Adjustments	3,861	(2,043)	1,152	(1,053)
Accumulated other comprehensive income (loss), Unrealized Holding Gains (Losses) on Investments	2,829	2,574	1,339	960
Accumulated Other Comprehensive Income (Loss)	6,690	531	2,491	(93)
Noncontrolling Interest [Member]
Accumulated other comprehensive income (loss), Foreign Currency Translation Adjustments	(451)	1,369	666	1,351
Accumulated other comprehensive income (loss), Unrealized Holding Gains (Losses) on Investments	0	0	0	0
Accumulated Other Comprehensive Income (Loss)	$ (451)	$ 1,369	$ 666	$ 1,351

Commitments And Contingencies (Schedule Of Noncancellable Minimum Commitments) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Commitments and Contingencies Disclosure [Abstract]
Minimum payments due, one year	$ 15,138
Minimum payments due, two years	6,283
Minimum payments due, three years	2,807
Minimum payments due, four years	2,170
Minimum payments due, thereafter	9,193
Operating leases, future minimum payments due	$ 35,591

- Definition

Amount of required minimum rental payments for leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References+ Details

- Definition

Amount of required minimum rental payments maturing in the next fiscal year following the latest fiscal year for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References+ Details

- Definition

Amount of required minimum rental payments maturing in the forth fiscal year following the latest fiscal year for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References+ Details

- Definition

Amount of required minimum rental payments maturing in the third fiscal year following the latest fiscal year for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References+ Details

- Definition

Amount of required minimum rental payments maturing in the second fiscal year following the latest fiscal year for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References+ Details

- Definition

Amount of required minimum rental payments maturing after the fifth fiscal year following the latest fiscal year for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References+ Details

Income Taxes (Schedule Of Federal And State And Foreign Income Tax Provision) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Expense (Benefit) [Abstract]
Federal, current	$ 112,247	$ 99,448	$ 116,388
State, current	5,284	7,067	8,698
Foreign, current	4,511	4,603	3,365
Current federal, state and foreign income tax	122,042	111,118	128,451
Federal, deferred	(2,708)	(2,317)	6,085
State, deferred	(2,199)	2,477	1,509
Foreign, deferred	3,970	6	0
Deferred income tax expense (benefit)	(937)	166	7,594
Income taxes attributable to the Noncontrolling interest	357	553	416
Total income taxes	$ 121,462	$ 111,837	$ 136,461

Income Taxes (Components Of Net Income Before Income Taxes) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Disclosure [Abstract]
Domestic	$ 319,907	$ 309,391	$ 360,937
Foreign	8,046	6,852	6,795
Income Loss From Continuing Operations Before Income Taxes And Minority Interest	$ 327,953	$ 316,243	$ 367,732

Income Taxes (Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate) (Details)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Statutory rate									35.00%	35.00%	35.00%
State taxes, net of Federal tax benefit									1.00%	2.00%	2.00%
Foreign tax expense and tax rate differential									1.60%	0.60%	0.40%
Research and development tax credit									0.00%	(0.70%)	(0.50%)
Domestic Production Activities Deduction									(0.60%)	(0.70%)	0.00%
Valuation allowance on capital losses and PA loss carryforwards									(0.30%)	0.00%	0.00%
Domestic Production Activities Deduction, prior years, net									0.00%	(1.50%)	0.00%
Effective Income Tax Rate Reconciliation, Tax Contingencies									0.50%	0.40%	0.20%
Effective Income Tax Rate Reconciliation, Other Adjustments									(0.30%)	0.10%	(0.10%)
Effective Income Tax Rate, Continuing Operations, Total	35.00%	39.00%	36.60%	37.20%	34.70%	33.80%	34.70%	37.10%	36.90%	35.20%	37.00%
Effective Income Tax Rate Reconciliation, Tax Contingencies, Domestic									0.15%	0.25%	0.14%
Effective Income Tax Rate Reconciliation, Tax Contingencies, State and Local									0.33%	0.14%	0.06%
Effective Income Tax Rate Reconciliation, Tax Contingencies, Foreign									0.02%	0.01%

Income Taxes (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Tax Disclosure [Abstract]
Undistributed earnings of foreign subsidiaries	$ 47,385
Unrecognized tax benefit, excluding interest and penalties	11,553	9,410	5,723	4,989
Unrecognized tax benefits that would affect effective tax rate	9,965
Amount included in Current liabilities	5,291
Amount included in Other long-term liabilities	7,032	8,276
Amount of previously unrecognized tax benefits recognized	1,944
Tax related interest and penalties	770	634	690
Unrecognized tax benefits within the next 12 months	$ 5,291

Income Taxes (Schedule Of Deferred Tax Assets and Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deferred Tax Liabilities, Net, Classification [Abstract]
Gross assets	$ 2,012	$ 1,151
Gross liabilities	0	(1)
Current deferred income tax assets and liabilities	2,012	1,150
Valuation allowance	0	0
Current deferred income taxes	2,012	1,150
Gross assets	63,129	63,374
Gross liabilities	(149,708)	(148,540)
Long term deferred income tax assets and liabilities	(86,579)	(85,166)
Valuation allowance	(6,879)	(8,585)
Long term deferred income taxes	(93,458)	(93,751)
Net deferred income tax liability	$ (91,446)	$ (92,601)

Income Taxes (Tax Effect Of Significant Temporary Differences Representing Deferred Tax Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deferred Tax Liabilities, Net [Abstract]
Difference in financial reporting and income tax depreciation methods	$ (10,104)	$ (13,600)
Reserves not currently deductible	325	374
Capitalized software currently deductible for tax purposes, net of amortization	(137,467)	(139,455)
State deferred income taxes	5,943	6,717
Revenue and expense recognized in different periods for financial reporting and income tax purpose	4,397	3,149
Unrealized holding loss (gain) on investments	(1,428)	(927)
Stock-based compensation expense	42,133	43,879
State net operating loss carryforward	13,883	14,485
Valuation allowance on deferred tax assets	(6,879)	(8,585)
Federal benefit of state tax deduction for uncertain tax positions	2,359	1,725
Foreign currency exchange	(39)	(363)
Foreign deferred including taxes on cumulative undistributed earnings of SEI AK	(4,569)	0
Net deferred income tax liability	$ (91,446)	$ (92,601)

Income Taxes (Unrecognized Tax Benefit) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Disclosure [Abstract]
Unrecognized tax benefits, Beginning Balance	$ 9,410	$ 5,723	$ 4,989
Gross additions, current year	2,196	2,392	1,372
Gross reductions, current year	0	0	0
Tax positions related to current year	2,196	2,392	1,372
Gross additions, prior year	1,990	1,992	0
Gross reductions, prior year	0	0	(104)
Tax positions related to current year	1,990	1,992	(104)
Settlements	(99)	0	(102)
Lapses on statute of limitations	(1,944)	(697)	(432)
Unrecognized tax benefits, Ending Balance	$ 11,553	$ 9,410	$ 5,723

Business Segment Information (Schedule Of Financial Information About Business Segments) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Revenues	$ 261,635	$ 251,752	$ 241,237	$ 237,898	$ 226,247	$ 233,227	$ 237,760	$ 232,493	$ 992,522	$ 929,727	$ 900,835
Expenses									736,172	683,884	644,052
Operating profit (loss)									256,350	245,843	256,783
Operating margin									26.00%	26.00%	29.00%
Private Banks [Member]
Segment Reporting Information [Line Items]
Revenues									364,788	348,122	346,668
Expenses									357,001	339,339	310,633
Operating profit (loss)									7,787	8,783	36,035
Operating margin									2.00%	3.00%	10.00%
Investment Advisors [Member]
Segment Reporting Information [Line Items]
Revenues									202,703	189,780	183,378
Expenses									120,146	110,438	110,388
Operating profit (loss)									82,557	79,342	72,990
Operating margin									41.00%	42.00%	40.00%
Institutional Investors [Member]
Segment Reporting Information [Line Items]
Revenues									227,889	210,027	206,531
Expenses									116,546	106,585	106,934
Operating profit (loss)									111,343	103,442	99,597
Operating margin									49.00%	49.00%	48.00%
Investment Managers [Member]
Segment Reporting Information [Line Items]
Revenues									193,484	177,975	160,159
Expenses									127,525	115,963	103,421
Operating profit (loss)									65,959	62,012	56,738
Operating margin									34.00%	35.00%	35.00%
Investments In New Businesses [Member]
Segment Reporting Information [Line Items]
Revenues									3,658	3,823	4,099
Expenses									14,954	11,559	12,676
Operating profit (loss)									$ (11,296)	$ (7,736)	$ (8,577)

Business Segment Information (Reconciliation Of Total Operating Profit Reported For Business Segments To Income From Operations In Consolidated Statements Of Operations) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Total operating profit from segments above	$ 256,350	$ 245,843	$ 256,783
Corporate overhead expenses	(45,759)	(43,398)	(40,715)
Noncontrolling interest reflected in segments	975	1,620	1,465
Income from operations	$ 211,566	$ 204,065	$ 217,533

- Definition

Amount of net income or loss for the period allocated to noncontrolling shareholders, unit holders, partners, or other equity holders in one or more of the entities consolidated into the reporting entity's financial statements other than those noncontrolling interests already defined within the taxonomy.

+ References+ Details

Business Segment Information (Schedule Of Additional Information Pertaining To Business Segments) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Capital Expenditures	$ 54,074	$ 53,225	$ 52,340
Depreciation	22,586	21,471	21,902
Amortization	33,258	27,288	24,048
Assets	1,309,824	1,294,559
Private Banks [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	32,509	35,045	32,982
Depreciation	15,226	15,648	15,704
Amortization	22,218	18,081	15,100
Assets	481,602	457,333
Investment Advisors [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	11,193	11,933	11,691
Depreciation	1,981	2,251	2,384
Amortization	7,167	6,201	5,467
Assets	120,255	119,053
Institutional Investors [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	2,781	2,059	2,601
Depreciation	1,012	1,079	1,170
Amortization	1,208	864	1,213
Assets	99,461	80,133
Investment Managers [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	5,494	3,081	3,659
Depreciation	1,914	1,809	1,891
Amortization	804	580	820
Assets	118,221	95,760
Investments In New Businesses [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	632	577	608
Depreciation	1,716	114	148
Amortization	1,249	433	477
Assets	5,846	5,962
Total From Business Segments [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	52,609	52,695	51,541
Depreciation	21,849	20,901	21,297
Amortization	32,646	26,159	23,077
Assets	825,385	758,241
Corporate Overhead [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	1,465	530	799
Depreciation	737	570	605
Amortization	612	1,129	971
Assets	$ 484,439	$ 536,318

- Definition

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References+ Details

- Definition

The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

+ References+ Details

Business Segment Information Business Segment Information (Schedule of Revenues And Assets Based On Location) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenues	$ 261,635	$ 251,752	$ 241,237	$ 237,898	$ 226,247	$ 233,227	$ 237,760	$ 232,493	$ 992,522	$ 929,727	$ 900,835
Assets	1,309,824				1,294,559				1,309,824	1,294,559
United States [Member]
Revenues									843,407	785,506	767,068
Assets	1,066,451				1,098,643				1,066,451	1,098,643
International Operations [Member]
Revenues									149,115	144,221	133,767
Assets	$ 243,373				$ 195,916				$ 243,373	$ 195,916

- Definition

+ References+ Details

Related Party Transactions (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Related Party Transactions [Abstract]
Investment Advisory and Administration Fees	$ 380,645	$ 364,602	$ 354,341
Distribution and Servicing Fees	37,827	39,017	36,007
Brokerage commissions revenue	$ 1,213	$ 2,772	$ 4,875

Sale of SEI Asset Korea Sale of SEI Asset Korea (Narrative) (Details) (USD $) In Thousands, unless otherwise specified					3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2012 SEI Asset Korea Co., Ltd. [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage of Ownership before Transaction					56.10%
Disposal Group, Including Discontinued Operation, Segment that Includes Disposal Group					Private Banks
Assets	$ 1,309,824	$ 1,294,559			$ 54,783
Cash and Cash Equivalents, at Carrying Value	452,247	420,986	496,292	590,877	48,306
Accrued Income Taxes, Noncurrent					$ 4,815

- Definition

Carrying amount as of the balance sheet date of the unpaid sum of the known and estimated amounts payable to satisfy all domestic and foreign income tax obligations due beyond one year or the operating cycle, whichever is longer. Alternate captions include income taxes payable, noncurrent.

+ References+ Details

- Definition

+ References+ Details

- Definition

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash

-URI http://asc.fasb.org/extlink&oid=6506951

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 8, 9

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.1)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 7

-Footnote 1

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 1

-Article 5

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6361293&loc=d3e6676-107765

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3044-108585

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 7, 26

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Quarterly Financial Data (SIV-Related Gains (Losses)) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule of Available-for-sale Securities [Line Items]
Revenues	$ 261,635	$ 251,752	$ 241,237	$ 237,898	$ 226,247	$ 233,227	$ 237,760	$ 232,493	$ 992,522	$ 929,727	$ 900,835
Income before income taxes	87,544	83,501	78,501	79,950	68,603	74,900	82,820	92,164	329,496	318,487	369,781
Net income attributable to SEI	56,585	50,743	49,555	49,965	44,396	49,232	53,603	57,728	206,848	204,959	231,687
Basic earnings per common share	$ 0.33	$ 0.29	$ 0.28	$ 0.28	$ 0.25	$ 0.27	$ 0.29	$ 0.31	$ 1.19	$ 1.12	$ 1.23
Diluted earnings per common share	$ 0.32	$ 0.29	$ 0.28	$ 0.28	$ 0.25	$ 0.27	$ 0.29	$ 0.31	$ 1.18	$ 1.11	$ 1.22
Effective tax rates	35.00%	39.00%	36.60%	37.20%	34.70%	33.80%	34.70%	37.10%	36.90%	35.20%	37.00%
SIV Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Diluted earnings per common share	$ 0.02	$ 0.01	$ 0.00	$ 0.01	$ 0.00	$ 0.00	$ 0.01	$ 0.02
Total SIV-related gains (losses)	$ 5,897	$ 3,389	$ 1,072	$ 2,882	$ (738)	$ (792)	$ (1,944)	$ 6,864

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References

+ Details

- Definition

+ References+ Details

- Definition

A ratio calculated by dividing the reported amount of income tax expense attributable to continuing operations for the period by GAAP-basis pretax income from continuing operations.

+ References+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

+ Details

Schedule II - Valuation And Qualifying Accounts And Reserves (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Allowance For Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 924	$ 1,195	$ 3,348
Additions, Charged to Costs and Expenses	0	0	0
Additions, Charged to Other Accounts	0	0	0
(Deductions)	(119)	(271)	(2,153)
Balance at End of Year	805	924	1,195
Deferred Income Tax Valuation Allowance [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	8,585	9,008	6,217
Additions, Charged to Costs and Expenses	(1,706)	(423)	1,443
Additions, Charged to Other Accounts	0	0	1,348
(Deductions)	0	0	0
Balance at End of Year	$ 6,879	$ 8,585	$ 9,008

Variable Interest Entities - Investment Products (Details)	12 Months Ended
	Dec. 31, 2012
Variable Interest Entities - Investment Products [Abstract]
Percentage not approached by expected return on any VIE investment	50.00%