10-Q

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

(Mark One)*

x Quarterly report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

for the quarterly period ended March 31, 2012

or

¨ Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

for the transition period from              to             

0-10200

(Commission File Number)

SEI INVESTMENTS COMPANY

(Exact name of registrant as specified in its charter)

Pennsylvania	23-1707341
(State or other jurisdiction of incorporation or organization)	(IRS Employer Identification Number)

1 Freedom Valley Drive, Oaks, Pennsylvania 19456-1100

(Address of principal executive offices)

(Zip Code)

(610) 676-1000

(Registrant’s telephone number, including area code)

N/A

(Former name, former address and former fiscal year, if changed since last report)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  x    No  ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  x    No  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer	x	Accelerated filer	¨
Non-accelerated filer	¨  (Do not check if a smaller reporting company)	Smaller reporting company	¨

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  x

The number of shares outstanding of the registrant’s common stock as of April 30, 2012 was 175,533,170.

PART I. FINANCIAL INFORMATION

Item 1. Consolidated Financial Statements.

SEI Investments Company

Consolidated Balance Sheets

(unaudited)

(In thousands)

	March 31, 2012		December 31, 2011
Assets
Current Assets:
Cash and cash equivalents	$	388,127	$	420,986
Restricted cash		6,000		6,000
Receivables from regulated investment companies		34,983		25,800
Receivables, net of allowance for doubtful accounts of $876 and $924 (Note 4)		147,110		142,109
Deferred income taxes		422		1,150
Securities owned (Note 6)		21,053		20,949
Other current assets		19,644		17,957
Total Current Assets		617,339		634,951
Property and Equipment, net of accumulated depreciation of $186,510 and $182,453 (Note 4)		136,431		129,548
Capitalized Software, net of accumulated amortization of $124,281 and $117,100		311,229		309,133
Investments Available for Sale (Note 6)		84,214		83,008
Trading Securities (Note 6)		56,461		56,325
Investment in Unconsolidated Affiliate (Note 2)		66,691		60,954
Other Assets, net		21,261		20,640
Total Assets	$	1,293,626	$	1,294,559

The accompanying notes are an integral part of these consolidated financial statements.

Page 1 of 37

SEI Investments Company

Consolidated Balance Sheets

(unaudited)

(In thousands, except par value)

	March 31, 2012		December 31, 2011
Liabilities and Equity
Current Liabilities:
Accounts payable	$	2,241	$	1,999
Accrued liabilities (Note 4)		115,408		147,044
Deferred revenue		1,228		2,030
Total Current Liabilities		118,877		151,073
Deferred Income Taxes		92,477		93,751
Other Long-term Liabilities (Note 11)		10,832		8,276
Total Liabilities		222,186		253,100
Commitments and Contingencies (Note 12)
Equity:
SEI Investments shareholders’ equity:
Common stock, $.01 par value, 750,000 shares authorized; 175,469 and 176,506 shares issued and outstanding		1,755		1,765
Capital in excess of par value		587,971		577,949
Retained earnings		460,727		443,702
Accumulated other comprehensive income, net		4,091		1,900
Total SEI Investments shareholders’ equity		1,054,544		1,025,316
Noncontrolling interest		16,896		16,143
Total Equity		1,071,440		1,041,459
Total Liabilities and Equity	$	1,293,626	$	1,294,559

The accompanying notes are an integral part of these consolidated financial statements.

Page 2 of 37

SEI Investments Company

Consolidated Statements of Operations

(unaudited)

(In thousands, except per share data)

	Three Months Ended March 31,
	2012			2011
Revenues:
Asset management, administration and distribution fees	$	172,954		$	167,504
Information processing and software servicing fees		56,200			55,824
Transaction-based and trade execution fees		8,744			9,165
Total revenues		237,898			232,493
Expenses:
Subadvisory, distribution and other asset management costs		28,467			26,296
Software royalties and other information processing costs		6,477			7,017
Brokerage commissions		6,307			6,581
Compensation, benefits and other personnel		78,543			71,025
Stock-based compensation		4,033			3,732
Consulting, outsourcing and professional fees		26,955			25,998
Data processing and computer related		11,465			11,303
Facilities, supplies and other costs		14,508			14,102
Amortization		7,622			6,231
Depreciation		5,432			5,611
Total expenses		189,809			177,896
Income from operations		48,089			54,597
Net gain from investments		3,205			7,278
Interest and dividend income		1,487			1,544
Interest expense		(161	)		(204	)
Equity in earnings of unconsolidated affiliate		27,330			28,949
Net income before income taxes		79,950			92,164
Income taxes		29,715			34,124
Net income		50,235			58,040
Less: Net income attributable to the noncontrolling interest		(270	)		(312	)
Net income attributable to SEI Investments Company	$	49,965		$	57,728
Basic earnings per common share	$	.28		$	.31
Diluted earnings per common share	$	.28		$	.31

The accompanying notes are an integral part of these consolidated financial statements.

Page 3 of 37

SEI Investments Company

Consolidated Statements of Comprehensive Income

(unaudited)

(In thousands)

	Three Months Ended March 31,
	2012						2011
Net income				$	50,235					$	58,040
Other comprehensive income, net of tax:
Foreign currency translation adjustments					2,703						2,828
Unrealized holding loss on investments:
Unrealized holding gains (losses) during the period, net of income tax expense of $7 and $112		31						(170	)
Less: reclassification adjustment for gains realized in net income, net of income tax expense of $35 and $60		(60	)		(29	)		(103	)		(273	)
Total other comprehensive income, net of tax					2,674						2,555
Comprehensive income				$	52,909					$	60,595
Comprehensive income attributable to the noncontrolling interest					(753	)					(732	)
Comprehensive income attributable to SEI Investments Company				$	52,156					$	59,863

The accompanying notes are an integral part of these consolidated financial statements.

Page 4 of 37

SEI Investments Company

Consolidated Statements of Cash Flows

(unaudited)

(In thousands)

	Three Months Ended March 31,
	2012			2011
Cash flows from operating activities:
Net income	$	50,235		$	58,040
Adjustments to reconcile net income to net cash provided by operating activities		(11,011	)		296
Net cash provided by operating activities		39,224			58,336
Cash flows from investing activities:
Additions to property and equipment		(12,116	)		(7,368	)
Additions to capitalized software		(9,277	)		(10,655	)
Purchases of marketable securities		(9,646	)		(27,307	)
Prepayments and maturities of marketable securities		10,464			10,140
Sales of marketable securities		720			36,812
Sales of other investments		0			4,905
Net cash (used in) provided by investing activities		(19,855	)		6,527
Cash flows from financing activities:
Payments on long-term debt		0			(35,000	)
Purchase and retirement of common stock		(36,463	)		(39,501	)
Proceeds from issuance of common stock		12,362			10,594
Tax benefit on stock options exercised		(1,609	)		791
Payment of dividends		(26,518	)		0
Net cash used in financing activities		(52,228	)		(63,116	)
Net (decrease) increase in cash and cash equivalents		(32,859	)		1,747
Cash and cash equivalents, beginning of period		420,986			496,292
Cash and cash equivalents, end of period	$	388,127		$	498,039

The accompanying notes are an integral part of these consolidated financial statements.

Page 5 of 37

Notes to Consolidated Financial Statements

(all figures are in thousands except per share data)

Note 1. 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.

Basis of Presentation

The accompanying Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States of America. Certain financial information and accompanying note disclosure normally included in the Company’s Annual Report on Form 10-K has been condensed or omitted. The interim financial information is unaudited but reflects all adjustments (consisting of only normal recurring adjustments) which are, in the opinion of management, necessary for a fair statement of financial position of the Company as of March 31, 2012, the results of operations for the three months ended March 31, 2012 and 2011, and cash flows for the three month periods ended March 31, 2012 and 2011. These interim Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and the Notes to the Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2011.

There have been no significant changes in significant accounting policies during the three months ended March 31, 2012 as compared to the significant accounting policies described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2011.

Cash and Cash Equivalents

Cash and cash equivalents includes $224,019 and $281,760 at March 31, 2012 and December 31, 2011, respectively, primarily invested in SEI-sponsored open-ended money market mutual funds.

Restricted Cash

Restricted cash includes $5,000 at March 31, 2012 and December 31, 2011 segregated for regulatory purposes related to trade-execution services conducted by SEI Investments (Europe) Limited. Restricted cash also includes $1,000 at March 31, 2012 and December 31, 2011 segregated in special reserve accounts for the benefit of customers of the Company’s broker-dealer subsidiary, SEI Investments Distribution Co. (SIDCO), in accordance with certain rules established by the Securities and Exchange Commission for broker-dealers.

Page 6 of 37

Capitalized Software

The Company capitalized $9,277 and $10,655 of software development costs during the three months ended March 31, 2012 and 2011, respectively. As of March 31, 2012, capitalized software placed into service included on the accompanying Consolidated Balance Sheet had a weighted average remaining life of approximately 10.3 years. Amortization expense related to capitalized software was $7,181 and $5,981 during the three months ended March 31, 2012 and 2011, respectively.

Software development costs capitalized during the three months ended March 31, 2012 and 2011 relates to the continued development of the Global Wealth Platform (GWP). As of March 31, 2012, the net book value of GWP was $289,623, net of accumulated amortization of $94,826. Capitalized software development costs in-progress at March 31, 2012 associated with future releases to GWP were $20,830. GWP has an estimated useful life of 15 years and a weighted average remaining life of 10.3 years. Amortization expense for GWP was $7,064 and $5,840 during the three months ended March 31, 2012 and 2011, respectively.

Earnings per Share

The calculations of basic and diluted earnings per share for the three months ended March 31, 2012 and 2011 are:

		000,000		000,000		000,000
	For the Three Month Period Ended March 31, 2012
	Income (Numerator)		Shares (Denominator)		Per Share Amount
Basic earnings per common share	$	49,965		176,348	$	.28
Dilutive effect of stock options		0		1,320
Diluted earnings per common share	$	49,965		177,668	$	.28

		000,000		000,000		000,000
	For the Three Month Period Ended March 31, 2011
	Income (Numerator)		Shares (Denominator)		Per Share Amount
Basic earnings per common share	$	57,728		185,787	$	.31
Dilutive effect of stock options		0		2,708
Diluted earnings per common share	$	57,728		188,495	$	.31

Employee stock options to purchase 14,329,000 and 7,609,000 shares of common stock, with an average exercise price of $23.43 and $28.26, were outstanding during the three month periods ended March 31, 2012 and 2011, respectively, but not included in the computation of diluted earnings per common share because the effect on diluted earnings per common share would have been anti-dilutive.

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Statements of Cash Flows

For purposes of the Consolidated Statements of Cash Flows, the Company considers investment instruments purchased with an original maturity of three months or less to be cash equivalents.

The following table provides the details of the adjustments to reconcile net income to net cash provided by operating activities for the three months ended March 31:

	2012			2011
Net income	$	50,235		$	58,040
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation		5,432			5,611
Amortization		7,622			6,231
Equity in earnings of unconsolidated affiliate		(27,330	)		(28,949	)
Distributions received from unconsolidated affiliate		21,593			23,802
Stock-based compensation		4,033			3,732
Provision for losses on receivables		(48	)		(236	)
Deferred income tax expense		(517	)		2,345
Net realized gains from investments		(3,205	)		(7,278	)
Change in other long-term liabilities		2,556			294
Change in other assets		(1,385	)		(1,841	)
Other		2,656			3,036
Change in current asset and liabilities
Decrease (increase) in
Receivables from regulated investment companies		(9,183	)		824
Receivables		(4,413	)		(3,551	)
Other current assets		(1,687	)		(1,210	)
Increase (decrease) in
Accounts payable		242			(1,841	)
Accrued liabilities		(6,575	)		(151	)
Deferred revenue		(802	)		(522	)
Total adjustments		(11,011	)		296
Net cash provided by operating activities	$	39,224		$	58,336

Note 2. Investment in Unconsolidated Affiliate

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 small number of SEI-sponsored mutual funds. As of March 31, 2012, the Company’s total partnership interest in LSV was approximately 41 percent. 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 affiliate on the accompanying Consolidated Balance Sheets and its interest in the earnings of LSV is reflected in Equity in earnings of unconsolidated affiliate on the accompanying Consolidated Statements of Operations.

At March 31, 2012, the Company’s total investment in LSV was $66,691. The investment in LSV exceeded the underlying equity in the net assets of LSV by $3,608, of which $3,062 is considered goodwill embedded in the investment. The Company receives partnership distributions from LSV on a quarterly basis. The Company received partnership distribution payments from LSV for $21,593 and $23,802 in the three months ended March 31, 2012 and 2011, respectively.

The Company’s proportionate share in the earnings of LSV was $27,330 and $28,949 during the three months ended March 31, 2012 and 2011, respectively.

Page 8 of 37

The following table contains the condensed statements of operations of LSV for the three months ended March 31, 2012 and 2011:

	Three Months Ended March 31,
	2012		2011
Revenues	$	77,465	$	79,402
Net income		66,673		69,946

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 to slightly under 40 percent.

Guaranty Agreement

In April 2011, LSV Employee Group II, LLC agreed to purchase a partnership interest of an existing LSV employee for $4,300, of which $3,655 was financed through a term loan with Bank of America, N.A. (Bank of America). The Company provided an unsecured guaranty to the lenders of all the obligations of LSV Employee Group II, LLC. The lenders have the right to seek payment from the Company in the event of a default by LSV Employee Group II, LLC. 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 $219 during the three months ended March 31, 2012. As of March 31, 2012, the remaining unpaid principal balance of the term loan was $2,978. This amount is not reflected, nor is it required to be reflected, in the Company’s Consolidated Balance Sheet at March 31, 2012.

The Company’s direct interest in LSV is unchanged as a result of this transaction. The Company has determined that LSV Employee Group II is a variable interest entity (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.

In April 2012, LSV Employee Group II made a principal payment of $249. As of April 30, 2012, the remaining unpaid principal balance of the term loan was $2,729. 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.

Note 3. 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 and net capital gains 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. Some of the Company’s investment products have been determined to be VIEs at inception.

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 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, is not 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 not significant. 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 not significant to the total assets of the Company.

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Note 4. Composition of Certain Financial Statement Captions

Receivables

Receivables on the accompanying Consolidated Balance Sheets consist of:

	March 31, 2012			December 31, 2011
Trade receivables	$	36,162		$	37,822
Fees earned, not billed		106,670			92,916
Other receivables		5,154			12,295
		147,986			143,033
Less: Allowance for doubtful accounts		(876	)		(924	)
	$	147,110		$	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.

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.

Property and Equipment

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

	March 31, 2012			December 31, 2011
Buildings	$	137,327		$	136,949
Equipment		63,350			64,256
Land		9,929			9,929
Purchased software		89,262			77,971
Furniture and fixtures		18,222			17,999
Leasehold improvements		4,743			4,558
Construction in progress		108			339
		322,941			312,001
Less: Accumulated depreciation		(186,510	)		(182,453	)
Property and Equipment, net	$	136,431		$	129,548

The Company recognized $5,432 and $5,611 in depreciation expense related to property and equipment for the three months ended March 31, 2012 and 2011, respectively.

Page 10 of 37

Accrued Liabilities

Accrued liabilities on the accompanying Consolidated Balance Sheets consist of:

	March 31, 2012		December 31, 2011
Accrued employee compensation	$	21,335	$	48,112
Accrued employee benefits and other personnel		5,816		5,408
Accrued consulting, outsourcing and professional fees		19,493		17,477
Accrued brokerage fees		8,415		8,665
Accrued sub-advisory, distribution and other asset management fees		16,500		17,091
Accrued income taxes		18,074		0
Accrued dividend payable		0		26,518
Other accrued liabilities		25,775		23,773
Total accrued liabilities	$	115,408	$	147,044

Note 5. 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 and Level 2 financial assets consist mainly of investments in equity and fixed-income mutual funds that are quoted daily and Government National Mortgage Association (GNMA) and other U.S. government agency securities that are single issuer pools that are valued based on current market data for the specific issue owned or pools of similar securities. Level 3 financial assets primarily consist of senior note obligations issued by SIVs. The Company did not have any Level 3 financial liabilities at March 31, 2012 or December 31, 2011. There were no transfers of financial assets between levels within the fair value hierarchy during the three months ended March 31, 2012.

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 a third party independent firm to assist in determining the fair value of the SIV security owned. Given the lack of any reliable market data on the SIV security, the firm utilized a valuation model that employs a net asset approach which considers the value of the underlying collateral of the SIV security to determine its fair value. Management evaluated the value received from the firm and considered other information, such as the existence of any current market activity, to determine the fair value of the SIV securities. As a result of this evaluation, the Company utilized the fair value of the SIV security without adjustment as provided by the third party 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

Page 11 of 37

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 may also consider, when available, price quotes from brokers and dealers. If a price quote is available, management will compare this number to the fair value derived from the valuation model of the independent firm giving consideration to other market factors and risk premiums. Given the lack of any significant trading activity for the SIV security owned by the Company, management believes that market prices may not represent the implied fair value of the SIV security owned by the Company.

In the event a market transaction does exist for a SIV security, management evaluates the publicly available information surrounding the transaction in order to assess if the price used represents the fair value for the SIV security. In management’s opinion, the current market for SIV securities does not represent any orderly and efficient market.

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

	At March 31, 2012
	Fair Value Measurements at Reporting Date Using
Assets	Total		Quoted Prices in Active  Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Equity available-for-sale securities	$	12,847	$	12,847	$	0	$	0
Fixed income available-for-sale securities		71,367		0		71,367		0
Fixed income securities owned		21,053		0		21,053		0
Trading securities		56,461		4,220		0		52,241
	$	161,728	$	17,067	$	92,420	$	52,241

	At December 31, 2011
	Fair Value Measurements at Reporting Date Using
Assets	Total		Quoted Prices in Active  Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Equity available-for-sale securities	$	8,010	$	8,010	$	0	$	0
Fixed income available-for-sale securities		74,998		0		74,998		0
Fixed income securities owned		20,949		0		20,949		0
Trading securities		56,325		3,702		0		52,623
	$	160,282	$	11,712	$	95,947	$	52,623

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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, 2012 to March 31, 2012:

	Trading Securities
Balance, January 1, 2012	$	52,623
Purchases		0
Issuances		0
Principal prepayments and settlements		(3,267	)
Sales		0
Total gains or (losses) (realized/unrealized):
Included in earnings		2,885
Included in other comprehensive income		0
Transfers in and out of Level 3		0
Balance March 31, 2012	$	52,241

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 March 31, 2011:

	Trading Securities
Balance, January 1, 2011	$	100,645
Purchases		0
Issuances		0
Principal prepayments and settlements		(3,441	)
Sales		(34,706	)
Total gains or (losses) (realized/unrealized):
Included in earnings		6,864
Included in other comprehensive income		0
Transfers in and out of Level 3		0
Balance March 31, 2011	$	69,362

Note 6. Marketable Securities

Investments Available for Sale

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

	As of March 31, 2012
	Cost Amount		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
SEI-sponsored mutual funds	$	12,744	$	84	$	(13	)	$	12,815
Other mutual funds		28		4		0			32
Debt securities		67,407		3,960		0			71,367
	$	80,179	$	4,048	$	(13	)	$	84,214

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	As of December 31, 2011
	Cost Amount		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
SEI-sponsored mutual funds	$	8,243	$	48	$	(360	)	$	7,931
Other mutual funds		69		10		0			79
Debt securities		70,604		4,394		0			74,998
	$	78,916	$	4,452	$	(360	)	$	83,008

Net unrealized holding gains at March 31, 2012 and December 31, 2011 were $2,545 (net of income tax expense of $1,490) 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.

Gross realized gains and losses from available-for-sale securities during the three months ended March 31, 2012 and 2011 were minimal. 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 classified as available-for-sale securities are issued by GNMA and are backed by the full faith and credit of the U.S. government. These securities were purchased to satisfy applicable regulatory requirements of SEI Private Trust Company (SPTC) and have maturity dates which range from 2020 to 2041.

Trading Securities

Trading securities of the Company consist of:

	As of March 31, 2012
	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Fair Value
SIV securities	$	143,096	$	0	$	(92,073	)	$	51,023
LSV-sponsored mutual funds		2,049		2,171		0			4,220
Other investments		1,215		3		0			1,218
	$	146,360	$	2,174	$	(92,073	)	$	56,461

	As of December 31, 2011
	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Fair Value
SIV securities	$	146,363	$	0	$	(94,955	)	$	51,408
LSV-sponsored mutual funds		2,049		1,653		0			3,702
Other investments		1,215		0		0			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 the three months ended March 31, 2012 and 2011, the Company recognized gains from SIV securities of $2,882 and $6,864, respectively. Of the gains recognized during the three months ended March 31, 2012, $2,111 resulted from cash payments received from the SIV securities and $771 was from an increase in fair value at March 31, 2012. Of the gains recognized during the three

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months ended March 31, 2011, $2,049 resulted from cash payments received from the SIV securities and $4,815 was from an increase in fair value at March 31, 2011. The net gains from the SIV securities are reflected in Net gain from investments on the accompanying Consolidated Statements of Operations.

In January 2011, the Company sold the senior note obligation originally issued by Stanfield Victoria. There was no gain or loss recognized by the Company from the sale of the note in 2011 as the fair value of the Stanfield Victoria note at December 31, 2010 was not different than the sale price received.

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 and Australian companies as well as various other global securities. The underlying securities held by the funds are translated into U.S. dollars within the funds. The net gains (losses) from the change in fair value of the funds during the three months ended March 31, 2012 and 2011 were minimal.

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 $21,053 and $20,949 at March 31, 2012 and December 31, 2011, respectively. The net gains (losses) from the change in fair value of the securities during the three months ended March 31, 2012 and 2011 were minimal.

Note 7. 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 replaced the five-year Credit Agreement with JP Morgan Chase Bank, N.A. The Credit Facility 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 LIBOR. There is also a commitment fee equal to 0.15 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 agreement may be terminated. The Company had no borrowings through the Credit Facility at March 31, 2012. The Company was in compliance with all covenants of the Credit Facility at March 31, 2012.

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 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 the three months ended March 31, 2012.

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Note 8. 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. All outstanding stock options have performance-based vesting provisions specific to each option grant that tie the vesting of the applicable stock options to the Company’s financial performance. The Company’s stock options vest at a rate of 50 percent when specified diluted earnings per share targets are achieved, and the remaining 50 percent when secondary, higher specified diluted earnings per share targets are achieved. The amount of stock-based compensation expense is based upon management’s estimate of when the earnings per share targets may be achieved.

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. No options are available for grant from this plan. Grants made from the 1998 Plan continue in effect under the terms of the grant.

The Company recognized stock-based compensation expense in its Consolidated Financial Statements in the three months ended March 31, 2012 and 2011, respectively, as follows:

	Three Months Ended March 31,
	2012			2011
Stock-based compensation expense	$	4,033		$	3,732
Less: Deferred tax benefit		(1,521	)		(1,398	)
Stock-based compensation expense, net of tax	$	2,512		$	2,334

As of March 31, 2012, there was approximately $45,594 of unrecognized compensation cost remaining, adjusted for estimated forfeitures, related to unvested employee stock options that management expects will vest and is being amortized. The Company estimates that compensation cost will be recognized according to the following schedule:

Period	Stock-Based Compensation Expense
Remainder of 2012	$	11,837
2013		12,715
2014		12,521
2015		3,850
2016		2,358
2017		2,313
	$	45,594

The Company issues new common shares associated with the exercise of stock options. The total intrinsic value of options exercised during the three months ended March 31, 2012 was $3,752. The total options exercisable as of March 31, 2012 had an intrinsic value of $36,218. The total intrinsic value for options exercisable is calculated as the difference between the market value of the Company’s common stock as of March 31, 2012 and the exercise price of the shares. The market value of the Company’s common stock as of March 31, 2012 was $20.69 as reported by the Nasdaq Stock Market, LLC. The weighted average exercise price of the options exercisable as of March 31,

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2012 was $17.36. Total options that were outstanding and exercisable as of March 31, 2012 were 26,082,000 and 10,873,000, respectively.

Common Stock Buyback

The Company’s Board of Directors, under multiple authorizations, has authorized the repurchase of the Company’s common stock on the open market or through private transactions. The Company purchased 1,848,000 shares at a total cost of $37,714 during the three months ended March 31, 2012. As of March 31, 2012, the Company has $58,562 of authorization remaining for the purchase of common stock under the program.

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.

Noncontrolling Interest

The following table provides a reconciliation of Noncontrolling interest on the Consolidated Balance Sheet for the period from January 1, 2012 to March 31, 2012:

	Noncontrolling interest
Balance, January 1, 2012	$	16,143
Net income attributable to noncontrolling interest		270
Foreign currency translation adjustments		483
Balance, March 31, 2012	$	16,896

The following table provides a reconciliation of Noncontrolling interest on the Consolidated Balance Sheet for the period from January 1, 2011 to March 31, 2011:

	Noncontrolling interest
Balance, January 1, 2011	$	15,155
Net income attributable to noncontrolling interest		312
Foreign currency translation adjustments		420
Balance, March 31, 2011	$	15,887

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Note 9. Accumulated Comprehensive Income (Loss)

Accumulated other comprehensive income (loss), net of tax, consists of:

	Foreign Currency Translation Adjustments			Unrealized Holding Gains (Losses) on Investments			Accumulated Other Comprehensive Income (Loss)
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			0			1,369
Total accumulated comprehensive income attributable to SEI Investments Company at December 31, 2011	$	(674	)	$	2,574		$	1,900
Total comprehensive income for the three months ended March 31, 2012	$	2,703		$	(29	)	$	2,674
Less: Total comprehensive income attributable to noncontrolling interest for the three months ended March 31, 2012		(483	)		0			(483	)
Total comprehensive income attributable to SEI Investments Company for the three months ended March 31, 2012	$	2,220		$	(29	)	$	2,191
Total accumulated comprehensive income at March 31, 2012	$	660		$	2,545		$	3,205
Less: Total accumulated comprehensive loss attributable to noncontrolling interest at March 31, 2012		886			0			886
Total accumulated comprehensive income attributable to SEI Investments Company at March 31, 2012	$	1,546		$	2,545		$	4,091

Note 10. 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

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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.

The information in the following tables is derived from the Company’s internal financial reporting used for corporate management purposes. There are no inter-segment revenues for the three months ended March 31, 2012 and 2011. Management evaluates Company assets on a consolidated basis during interim periods. The accounting policies of the reportable business segments are the same as those described in Note 1 to the Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2011.

The following tables highlight certain unaudited financial information about each of the Company’s business segments for the three months ended March 31, 2012 and 2011.

	Private Banks			Investment Advisors			Institutional Investors			Investment Managers			Investments In New Businesses			Total
	For the Three Months Ended March 31, 2012
Revenues	$	87,988		$	49,468		$	53,317		$	46,211		$	914		$	237,898
Expenses		87,517			29,301			28,100			30,426			3,698			179,042
Operating profit (loss)	$	471		$	20,167		$	25,217		$	15,785		$	(2,784	)	$	58,856
Operating margin		1	%		41	%		47	%		34	%		N/A			25	%

	Private Banks			Investment Advisors			Institutional Investors			Investment Managers			Investments In New Businesses			Total
	For the Three Months Ended March 31, 2011
Revenues	$	86,709		$	48,108		$	53,185		$	43,441		$	1,050		$	232,493
Expenses		82,403			27,040			26,953			27,999			3,125			167,520
Operating profit (loss)	$	4,306		$	21,068		$	26,232		$	15,442		$	(2,075	)	$	64,973
Operating margin		5	%		44	%		49	%		36	%		N/A			28	%

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

	2012			2011
Total operating profit from segments above	$	58,856		$	64,973
Corporate overhead expenses		(11,082	)		(10,648	)
Noncontrolling interest reflected in segments		315			272
Income from operations	$	48,089		$	54,597

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The following tables provide additional information for the three months ended March 31, 2012 and 2011 pertaining to our business segments:

	Capital Expenditures				Depreciation
	2012		2011		2012		2011
Private Banks	$	11,842	$	11,030	$	3,728	$	4,038
Investment Advisors		4,141		3,742		494		591
Institutional Investors		1,231		881		262		292
Investment Managers		3,053		1,784		476		503
Investments in New Businesses		272		212		334		30
Total from business segments	$	20,539	$	17,649	$	5,294	$	5,454
Corporate Overhead		854		374		138		157
	$	21,393	$	18,023	$	5,432	$	5,611

	Amortization
	2012		2011
Private Banks	$	4,685	$	4,229
Investment Advisors		1,716		1,418
Institutional Investors		302		167
Investment Managers		201		115
Investments in New Businesses		277		59
Total from business segments	$	7,181	$	5,988
Corporate Overhead		441		243
	$	7,622	$	6,231

Note 11. Income Taxes

The gross liability for unrecognized tax benefits at March 31, 2012 and December 31, 2011 was $11,757 and $9,410, respectively, exclusive of interest and penalties, of which $10,043 and $8,320 would affect the effective tax rate if the Company were to recognize the tax benefit.

The Company classifies interest and penalties on unrecognized tax benefits as income tax expense. As of March 31, 2012 and December 31, 2011, the combined amount of accrued interest and penalties related to tax positions taken on tax returns was $843 and $634, respectively.

	March 31, 2012		December 31, 2011
Gross liability for unrecognized tax benefits, exclusive of interest and penalties	$	11,757	$	9,410
Interest and penalties on unrecognized benefits		843		634
Total gross uncertain tax positions	$	12,600	$	10,044
Amount included in Current liabilities	$	1,768	$	1,768
Amount included in Other long-term liabilities		10,832		8,276
	$	12,600	$	10,044

The Company’s effective tax rates were 37.2 percent and 37.1 percent for the three months ended March 31, 2012 and 2011, respectively. The Company files income tax returns in the United States on a consolidated basis and in many U.S. state and foreign jurisdictions. The Company is subject to examination of income tax returns by the Internal Revenue Service (IRS) and other domestic and

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foreign tax authorities. The Company is no longer subject to U.S. federal income tax examination for years before 2007 and is no longer subject to state, local or foreign income tax examinations by authorities for years before 2006.

The Company estimates it will recognize $1,768 of unrecognized tax benefits within the next twelve months due to the expiration of the statute of limitations and resolution of income tax audits. These unrecognized tax benefits are related to tax positions taken on certain federal, state, and foreign tax returns. However, the timing of the resolution of income tax examinations is highly uncertain, and the amounts ultimately paid, if any, upon resolution of the issues raised by the taxing authorities may differ materially from the amounts accrued for each year. While it is reasonably possible that some issues under examination could be resolved in the next twelve months, based upon the current facts and circumstances, the Company cannot reasonably estimate the timing of such resolution or total range of potential changes as it relates to the current unrecognized tax benefits that are recorded as part of the Company’s financial statements.

Note 12. Commitments and Contingencies

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. To date, the Complaints have been filed in the United States District Court for the Southern District of New York and in the United States District Court for the District of Maryland. The three complaints filed in the District of Maryland have been voluntarily dismissed by the plaintiffs. Two of them were subsequently re-filed in the Southern District of New York. Two of the complaints filed in the Southern District of New York have also been voluntarily dismissed by plaintiffs. 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. The Complaints allege that SIDCO is liable for these purportedly material misstatements and omissions under Section 11 of the Securities Act of 1933. The Complaints seek unspecified compensatory and other damages, reasonable costs and other relief. Defendants have moved to consolidate the complaints, which motion has been granted. The Court appointed lead plaintiff on July 13, 2010, and an amended consolidated class action complaint was filed on September 25, 2010 asserting substantially the same claims. Defendants moved to dismiss on November 15, 2010. On December 16, 2010, lead plaintiff informed the Court and Defendants that lead plaintiff elected to file a second amended consolidated complaint, which was filed on January 31, 2011. Defendants filed a motion to dismiss the second complaint on March 17, 2011. Oral argument on this motion was held on February 2, 2012. 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. 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 putative 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

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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 have been removed to federal court, and plaintiffs’ motions to remand are pending. These two cases have been 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 and SPTC in the two remanded actions were preempted by federal law and the Court dismissed these cases with prejudice. The Court of Appeals for the Fifth Circuit granted an expedited appeal of the United States District Court’s order and judgment. The appeal was briefed, and oral argument was held on February 7, 2012. 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 April 2, 2012, SEI filed with the United States Court of Appeals for the Fifth Circuit a petition for rehearing en banc of the panel’s opinion. On April 19, 2012, the Fifth Circuit Court of Appeals denied the petition for rehearing.

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. SEI and SPTC filed exceptions in the putative 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 putative 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. Following the decision by the United States District Court for the Northern District of Texas, the Court in the East Baton Rouge action issued an order staying the proceedings in the East Baton Rouge class action pending the outcome of the appeal of the order and judgment of the United States District Court for the Northern District of Texas. Following the panel opinion of the Court of Appeals on March 19, 2012, the Court in the East Baton Rouge action scheduled a hearing on class certification for September 20, 2012. 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.

Because of the uncertainty of the make-up of the classes, the specific theories of liability that may survive a motion to dismiss, 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.

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Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

(In thousands, except asset balances and per share data)

This discussion reviews and analyzes the consolidated financial condition at March 31, 2012 and 2011, the consolidated results of operations for the three months ended March 31, 2012 and 2011 and other key factors that may affect future performance. This discussion should be read in conjunction with the Consolidated Financial Statements and the Notes to the Consolidated Financial Statements.

Overview

Consolidated Summary

We are a leading global provider of investment processing, investment management, and investment operations solutions. We help corporations, financial institutions, financial advisors, and ultra-high-net-worth families create and manage wealth by providing comprehensive, innovative, investment and investment-business solutions. Investment processing fees are earned as monthly fees for contracted services, including computer processing services, software licenses, and investment operations services, as well as transaction-based fees for providing securities valuation and trade-execution. Investment operations and investment management fees are earned as a percentage of average assets under management or administration. As of March 31, 2012, through our subsidiaries and partnerships in which we have a significant interest, we manage or administer $427.8 billion in mutual fund and pooled or separately managed assets, including $188.6 billion in assets under management and $239.2 billion in client assets under administration. Our affiliate, LSV Asset Management (LSV), manages $60.6 billion of assets which are included as assets under management.

Our Condensed Consolidated Statements of Operations for the three months ended March 31, 2012 and 2011 were:

	Three Months Ended March 31,						Percent
	2012			2011			Change
Revenues	$	237,898		$	232,493			2	%
Expenses		189,809			177,896			7	%
Income from operations		48,089			54,597			(12	%)
Net gain from investments		3,205			7,278			(56	%)
Interest income, net of interest expense		1,326			1,340			(1	%)
Equity in earnings from unconsolidated affiliate		27,330			28,949			(6	%)
Income before income taxes		79,950			92,164			(13	%)
Income taxes		29,715			34,124			(13	%)
Net income		50,235			58,040			(13	%)
Less: Net income attributable to noncontrolling interest		(270	)		(312	)		(13	%)
Net income attributable to SEI Investments Co.	$	49,965		$	57,728			(13	%)
Diluted earnings per common share	$	.28		$	.31			(10	%)

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In our opinion, the following items had a significant impact on our financial results for the three month periods ended March 31, 2012 and 2011:

• Revenue growth was primarily driven by higher Asset management, administration and distribution fees from improved cash flows and market appreciation occurring in late 2011 and into the first quarter 2012. Our average assets under management, excluding LSV, increased $9.6 billion, or eight percent, to $124.1 billion in the first quarter 2012 as compared to $114.5 billion during the first quarter 2011.

• New business coupled with asset funding from existing clients for our hedge fund solutions and increased accounts for our separately managed accounts solutions in our Investment Managers segment also served to drive revenue growth.

• Our percentage ownership of LSV remained at approximately 41 percent. Our proportionate share in the earnings of LSV in the first quarter 2012 was $27.3 million, as compared to $28.9 million in first quarter 2011, a decrease of six percent. Despite the favorable market conditions in late 2011 and first quarter 2012, LSV’s revenues decreased due to cash outflows in early 2011 and the sharp market decline in third quarter 2011 which resulted in a net decline in the value of assets under management. LSV’s average assets under management were $59.2 billion during the first quarter 2012, as compared to $62.2 billion during the first quarter 2011, a decrease of five percent.

• Our operating expenses related to servicing new and existing clients of our Global Wealth Services solution implemented on the Global Wealth Platform increased during the first quarter 2012 as compared to first quarter 2011 as we continue to build out the operational infrastructure and add new functionality to the platform. A higher portion of these costs are not capitalized. These increased operational costs, mainly related to personnel, primarily impacted the Private Banks and Investment Advisors segments. The increased operational costs are included in Compensation, benefits and other personnel on the accompanying Consolidated Statements of Operations.

• Our operating expenses related to our hedge fund and separately managed accounts solutions of our Investment Managers segment increased during the first quarter 2012 as compared to first quarter 2011. These increased operational costs, mainly related to personnel, resulted from servicing new and existing clients and are also included in Compensation, benefits and other personnel on the accompanying Consolidated Statements of Operations.

• Sales events, net of client losses, were significantly higher during the first quarter 2012. These sales events resulted in an increase in sales compensation expense of $1.8 million when compared to first quarter 2011.

• We recognized $2.9 million in gains from structured investment vehicles (SIV) securities during the first quarter 2012 as compared to gains of $6.9 million during the first quarter 2011. Approximately $2.1 million of the gain in 2012 resulted from cash payments received from the SIV securities that had been previously written down.

• We continued our stock repurchase program during 2012 and purchased 1,848,000 shares at an average price of approximately $20 per share in the first quarter of 2012.

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Ending Asset Balances

This table presents ending assets of our clients, or of our clients’ customers, for which we provide management or administrative services through our subsidiaries and partnerships in which we have a significant interest. These assets are not included in our balance sheets because we do not own them.

Ending Asset Balances

(In millions)

	As of March 31,				Percent
	2012		2011		Change
Private Banks:
Equity and fixed income programs	$	17,180	$	14,809		16	%
Collective trust fund programs		435		576		(24	%)
Liquidity funds		5,549		5,217		6	%
Total assets under management	$	23,164	$	20,602		12	%
Client proprietary assets under administration		10,916		11,227		(3	%)
Total assets	$	34,080	$	31,829		7	%
Investment Advisors:
Equity and fixed income programs		29,722		28,296		5	%
Collective trust fund programs		1,199		1,618		(26	%)
Liquidity funds		1,643		1,551		6	%
Total assets under management	$	32,564	$	31,465		3	%
Institutional Investors:
Equity and fixed income programs		54,537		51,287		6	%
Collective trust fund programs		424		608		(30	%)
Liquidity funds		3,725		3,202		16	%
Total assets under management	$	58,686	$	55,097		7	%
Investment Managers:
Equity and fixed income programs		62		37		68	%
Collective trust fund programs		12,781		8,841		45	%
Liquidity funds		147		139		6	%
Total assets under management	$	12,990	$	9,017		44	%
Client proprietary assets under administration		228,327		238,335		(4	%)
Total assets	$	241,317	$	247,352		(2	%)
Investments in New Businesses:
Equity and fixed income programs		568		598		(5	%)
Liquidity funds		34		56		(39	%)
Total assets under management	$	602	$	654		(8	%)
LSV:
Equity and fixed income programs	$	60,607	$	62,370		(3	%)
Consolidated:
Equity and fixed income programs		162,676		157,397		3	%
Collective trust fund programs		14,839		11,643		27	%
Liquidity funds		11,098		10,165		9	%
Total assets under management	$	188,613	$	179,205		5	%
Client proprietary assets under administration		239,243		249,562		(4	%)
Total assets under management and administration	$	427,856	$	428,767		0	%

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Average Asset Balances

This table presents average asset balances of our clients, or of clients’ customers, for which we provide management or administrative services through our subsidiaries and partnerships in which we have a significant interest. These assets are not included in our balance sheets because we do not own them.

Average Asset Balances

(In millions)

	As of March 31,				Percent
	2012		2011		Change
Private Banks:
Equity and fixed income programs	$	17,116	$	14,170		21	%
Collective trust fund programs		436		593		(26	%)
Liquidity funds		5,581		5,058		10	%
Total assets under management	$	23,133	$	19,821		17	%
Client proprietary assets under administration		10,211		10,921		(7	%)
Total assets	$	33,344	$	30,742		8	%
Investment Advisors:
Equity and fixed income programs		28,426		27,841		2	%
Collective trust fund programs		1,238		1,687		(27	%)
Liquidity funds		2,015		1,580		28	%
Total assets under management	$	31,679	$	31,108		2	%
Institutional Investors:
Equity and fixed income programs		52,270		50,392		4	%
Collective trust fund programs		427		608		(30	%)
Liquidity funds		3,765		3,418		10	%
Total assets under management	$	56,462	$	54,418		4	%
Investment Managers:
Equity and fixed income programs		58		1		N/A
Collective trust fund programs		11,983		8,288		45	%
Liquidity funds		190		210		(10	%)
Total assets under management	$	12,231	$	8,499		44	%
Client proprietary assets under administration		224,547		237,376		(5	%)
Total assets	$	236,778	$	245,875		(4	%)
Investments in New Businesses:
Equity and fixed income programs		549		579		(5	%)
Liquidity funds		39		61		(36	%)
Total assets under management	$	588	$	640		(8	%)
LSV:
Equity and fixed income programs	$	59,200	$	62,212		(5	%)
Consolidated:
Equity and fixed income programs		157,619		155,195		2	%
Collective trust fund programs		14,084		11,176		26	%
Liquidity funds		11,590		10,327		12	%
Total assets under management	$	183,293	$	176,698		4	%
Client proprietary assets under administration		234,758		248,297		(5	%)
Total assets under management and administration	$	418,051	$	424,995		(2	%)

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In the preceding tables, assets under management are total assets of our clients or their customers invested in our equity and fixed-income investment programs, collective trust fund programs, and liquidity funds for which we provide asset management services. Assets under management and administration also include total assets of our clients or their customers for which we provide administrative services, including client proprietary fund balances for which we provide administration and/or distribution services.

Business Segments

Revenues, Expenses and Operating Profit (Loss) for our business segments for the three months ended March 31, 2012 compared to the three months ended March 31, 2011 were as follows:

	Three Months Ended March 31,						Percent Change
	2012			2011
Private Banks:
Revenues	$	87,988		$	86,709			1	%
Expenses		87,517			82,403			6	%
Operating Profit	$	471		$	4,306			(89	%)
Operating Margin		1	%		5	%
Investment Advisors:
Revenues	$	49,468		$	48,108			3	%
Expenses		29,301			27,040			8	%
Operating Profit	$	20,167		$	21,068			(4	%)
Operating Margin		41	%		44	%
Institutional Investors:
Revenues	$	53,317		$	53,185			0	%
Expenses		28,100			26,953			4	%
Operating Profit	$	25,217		$	26,232			(4	%)
Operating Margin		47	%		49	%
Investment Managers:
Revenues	$	46,211		$	43,441			6	%
Expenses		30,426			27,999			9	%
Operating Profit	$	15,785		$	15,442			2	%
Operating Margin		34	%		36	%
Investments in New Businesses:
Revenues	$	914		$	1,050			(13	%)
Expenses		3,698			3,125			18	%
Operating Loss	($	2,784	)	($	2,075	)		N/A
Operating Margin		N/A			N/A

For additional information pertaining to our business segments, see Note 10 to the Consolidated Financial Statements.

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Private Banks

	Three Months Ended March 31,				Percent Change
	2012		2011
Revenues:
Information processing and software servicing fees	$	55,752	$	55,446		1	%
Asset management, administration & distribution fees		25,109		23,918		5	%
Transaction-based and trade execution fees		7,127		7,345		(3	%)
Total revenues	$	87,988	$	86,709		1	%

Revenues increased $1.3 million, or one percent, compared to the prior year corresponding period and were primarily affected by:

• Increased investment management fees from existing international clients due to higher average assets under management from improved capital markets in late 2011 into the first quarter of 2012, in addition to positive cash flows; and

• Increased net investment processing fees from new Global Wealth Services clients implemented onto the Global Wealth Platform; offset by

• Lower recurring investment processing fees due to price reductions provided to existing clients that recontracted for longer periods and lower transaction volumes.

Operating margins decreased to one percent compared to five percent in the same period a year ago. Operating income decreased by $3.8 million or 89 percent, compared to the prior year corresponding period and was primarily affected by:

• Increased direct expenses associated with increased investment management fees from existing international clients, mainly distribution fees;

• Increased non-capitalized development costs, mainly personnel costs, and amortization expense relating to the Global Wealth Platform;

• Increased operational costs, mainly personnel costs, for servicing new and existing Global Wealth Services clients implemented onto the Global Wealth Platform;

• Increased sales compensation expense due to new business activity; and

• Increased one-time termination costs; partially offset by

• An increase in revenues.

Investment Advisors

Revenues increased $1.4 million, or three percent, compared to the prior year corresponding period and were primarily affected by:

• Increased investment management fees from existing clients due to higher average assets under management caused by improved capital markets in late 2011 and through the first quarter of 2012 and an increase in net cash flows from new and existing advisors; and

• An increase in the average basis points earned on our assets under management due to movement of assets into higher-yielding products.

Operating margins decreased to 41 percent compared to 44 percent in the same period a year ago. Operating income decreased slightly compared to the prior year corresponding period and was primarily affected by:

• Increased non-capitalized development costs and amortization expense relating to the Global Wealth Platform as well as spending associated with building the necessary functionality and infrastructure for servicing financial institutions and investment advisors in the United States;

• Increased sales compensation expense due to new business activity; and

• Increased one-time termination costs; partially offset by

• An increase in revenues.

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Institutional Investors

Revenues increased slightly compared to the prior year corresponding period and were primarily affected by:

• Increased investment management fees from existing clients due to higher average assets under management caused by improved capital markets in late 2011 and through the first quarter of 2012 as well as additional asset funding from existing clients; and

• Asset funding from new sales of our retirement and not-for-profit solutions; partially offset by

• Client losses and lower basis points earned on assets under management.

Operating margins decreased to 47 percent compared to 49 percent in the same period a year ago. Operating income decreased $1.0 million, or four percent, compared to the prior year corresponding period and was primarily affected by:

• Increased sales compensation expense due to new business activity and other personnel costs, mainly salary; and

• Increased discretionary marketing and promotion expenses; partially offset by

• An increase in revenues.

Investment Managers

Revenues increased $2.8 million, or six percent, compared to the prior year corresponding period and were primarily affected by:

• Cash flows from new clients of our hedge funds and collective trust fund solutions; partially offset by client losses;

• Net positive cash flows from existing hedge fund clients due to new funding along with higher valuations from capital market increases in late 2011 and through the first quarter of 2012; and

• Increased accounts from our separately managed account program due to new clients and existing clients involved in mergers.

Operating margins decreased to 34 percent compared to 36 percent in the same period a year ago. Operating income increased slightly compared to the prior year corresponding period and was primarily affected by:

• An increase in revenues; partially offset by

• Increased personnel expenses, technology and other operational costs to service new clients of our hedge fund and separately managed accounts solutions.

Other

Other income and expense items on the accompanying Consolidated Statements of Operations consists of:

	Three Months Ended March 31,
	2012			2011
Net gain from investments	$	3,205		$	7,278
Interest and dividend income		1,487			1,544
Interest expense		(161	)		(204	)
Equity in the earnings of unconsolidated affiliate		27,330			28,949
Total other income and expense items, net	$	31,861		$	37,567

Net gain from investments

Net gain from investments consists of:

	Three Months Ended March 31,
	2012			2011
Gains from SIV securities	$	2,882		$	6,864
Net realized and unrealized gains from marketable securities		619			414
Other losses		(296	)		0
Net gain from investments	$	3,205		$	7,278

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During the three months ended March 31, 2012, we recognized gains of $2.9 million from SIV securities, of which $2.1 million resulted from cash payments received from the SIV securities and $0.8 million from an increase in fair value at March 31, 2012.

During the three months ended March 31, 2011, we recognized gains of $6.9 million from SIV securities, of which $2.1 million resulted from cash payments received from the SIV securities and $4.8 million from an increase in fair value at March 31, 2011. In addition, we sold the senior note obligation originally issued by Stanfield Victoria. There was no gain or loss recognized 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.

Interest and dividend income

Interest and dividend income is earned based upon the amount of cash that is invested daily and the average yield earned on those balances.

Interest expense

Interest expense primarily includes fees related to our credit facility.

Equity in the earnings of unconsolidated affiliate

Equity in the earnings of unconsolidated affiliate on the accompanying Consolidated Statement of Operations includes our less than 50 percent ownership in LSV. Our total partnership interest in LSV remained at approximately 41 percent during the three month periods ended March 31, 2012 and 2011. Our proportionate share in the earnings of LSV was $27.3 million in first quarter 2012 as compared to $28.9 million in first quarter 2011, a decrease of six percent. LSV’s revenues decreased due to cash outflows in early 2011 coupled with the sharp market decline in third quarter 2011 despite improved capital market conditions in late 2011 and first quarter 2012. LSV’s ending assets under management decreased $1.8 billion to $60.6 billion at March 31, 2012 as compared to $62.4 billion at March 31, 2011, a decrease of three percent.

In March 2009, certain partners of LSV, including SEI, agreed to designate a portion of their partnership interest for the purpose of providing an interest in the partnership to a select group of key LSV employees. In April 2012, these contributing partners agreed to provide certain key LSV employees an interest in LSV thereby reducing our interest in LSV to slightly below 40 percent.

Noncontrolling interest

Noncontrolling interest includes the interest of other shareholders in a joint venture of the Company in an asset management firm located in South Korea.

Income Taxes

Our effective tax rates were 37.2 percent and 37.1 percent for the three months ended March 31, 2012 and 2011, respectively.

Fair Value Measurements

The fair value of our financial assets and liabilities is determined in accordance with the fair value hierarchy. The fair value of most of our financial assets are determined using Level 1 or Level 2 inputs and consist mainly of investments in equity or fixed-income mutual funds that are quoted daily and Government National Mortgage Association (GNMA) and other U.S. government agency securities that are single issuer pools that are valued based on current market data of similar assets. Our Level 3 financial assets consist mainly of SIV securities (See Note 5 to the Notes to Consolidated Financial Statements).

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Liquidity and Capital Resources

	Three Months Ended March 31,
	2012			2011
Net cash provided by operating activities	$	39,224		$	58,336
Net cash (used in) provided by investing activities		(19,855	)		6,527
Net cash used in financing activities		(52,228	)		(63,116	)
Net (decrease) increase in cash and cash equivalents		(32,859	)		1,747
Cash and cash equivalents, beginning of period		420,986			496,292
Cash and cash equivalents, end of period	$	388,127		$	498,039

Cash requirements and liquidity needs are primarily funded through our cash flow from operations and our capacity for additional borrowing. At March 31, 2012, our unused sources of liquidity consisted of cash and cash equivalents and the amount available under our credit facility.

In February 2012, we replaced our credit facility with a new five-year credit facility agreement which provides for borrowings of up to $300.0 million (See Note 7 to the Consolidated Financial Statements). The new credit facility is a senior unsecured revolving line of credit with Wells Fargo Bank, National Association, and a syndicate of other lenders and is scheduled to expire in February 2017. The availability of the new credit facility is subject to the compliance with certain covenants set forth in the agreement. The credit facility contains covenants which restrict our ability 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, we would also be restricted from paying dividends on, or repurchasing, our common stock. Currently, our ability to borrow from the credit facility is not limited by any covenant of the agreement. We currently have no borrowings under the new credit facility.

Our cash and cash equivalents include accounts managed by our subsidiaries and minority-owned subsidiaries that are used in their operations or to cover specific business and regulatory requirements. The availability of this cash for other purposes beyond the operations of these subsidiaries may be limited. As of April 30, 2012, the amount of cash and cash equivalents considered free and immediately accessible for other general corporate purposes was $262.9 million.

Cash flows from operations decreased $19.1 million in the first quarter of 2012 compared to the first quarter of 2011 due to the decline in net income and the net change in our working capital accounts, primarily from the change in the balances of receivables and accrued income taxes.

Cash flows from investing activities decreased $26.4 million in the first quarter of 2012 compared to the first quarter of 2011. Net cash used in investing activities includes:

• Purchases, sales and maturities of marketable securities. We had cash outflows of $9.6 million for the purchase of marketable securities in the first quarter of 2012 as compared to $27.3 million in the first quarter of 2011. Marketable securities purchased in 2012 and 2011 consisted of investments for the start-up of new investment products and investments in short-term U.S. government agency and commercial paper securities by SIDCO. Purchases of marketable securities in first quarter 2011 include $20.0 million of short-term U.S. government agency and commercial paper securities to initiate SIDCO’s investment program. We had cash inflows of $11.2 million from sales and maturities of marketable securities in the first quarter of 2012 as compared to $46.9 million in the first quarter of 2011. Marketable securities sold in 2011 primarily includes the proceeds from the sales of SIV securities. Cash inflows from maturities and prepayments of marketable securities were $10.4 million in the first quarter of 2012 as compared to $10.1 million in the first quarter of 2011.

• The capitalization of costs incurred in developing computer software. We will continue the development of the Global Wealth Platform through a series of releases to expand the functionality of the platform. We capitalized $9.3 million of software development costs in the first quarter of 2012 as compared to $10.7 million in the first quarter of 2011. Amounts capitalized in 2012 and 2011 include costs for significant enhancements and upgrades to the platform.

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• Capital expenditures. Our capital expenditures in the first quarter of 2012 primarily include purchased software. Our capital expenditures in the first quarter of 2011 primarily include equipment for our data center operations.

Cash flows from financing activities increased $10.9 million in the first quarter of 2012 compared to the first quarter of 2011. Net cash used in financing activities includes:

• The repurchase of our common stock. Our Board of Directors has authorized the repurchase of up to $1.928 billion worth of our common stock through multiple authorizations. Through April 30, 2012, we repurchased approximately 276.8 million shares of our common stock at a cost of $1.870 billion and had $58.6 million of authorization remaining for the purchase of our common stock under this program. We spent approximately $36.5 million during the first quarter of 2012 and $39.5 million during the first quarter of 2011 for the repurchase of our common stock. Currently, there is no expiration date for our common stock repurchase program.

• Dividend payments. Cash dividends paid were $26.5 million or $.15 per share in the first quarter of 2012. There were no cash dividends paid during the first quarter of 2011 since the payment date of the cash dividend declared in December 2010 occurred in 2010.

• Principal payments of our debt. Principal payments in the first quarter of 2011 include payments of $35.0 million to reduce the outstanding debt associated with our credit facility. We fully repaid the outstanding balance of our credit facility in 2011 and had no debt during the first quarter 2012.

We believe our operating cash flow, available borrowing capacity, and existing cash and cash equivalents should provide adequate funds for ongoing operations; continued investment in new products and equipment; our common stock repurchase program and future dividend payments.

Forward-Looking Information and Risk Factors

The Private Securities Litigation Reform Act of 1995 provides a “safe harbor” for forward-looking statements. Certain information contained in this discussion is or may be considered forward-looking. Forward-looking statements relate to future operations, strategies, financial results or other developments. Forward-looking statements are based upon estimates and assumptions that involve certain risks and uncertainties, many of which are beyond our control or are subject to change. Although we believe our assumptions are reasonable, they could be inaccurate. Our actual future revenues and income could differ materially from our expected results. We have no obligation to publicly update or revise any forward-looking statements.

Among the risks and uncertainties which may affect our future operations, strategies, financial results or other developments are those risks described in our latest Annual Report on Form 10-K in Part I, Item 1A. These risks include the following:

• changes in capital markets that may affect our revenues and earnings;

• product development risk;

• consolidation within our target markets, including consolidations between banks and other financial institutions;

• risk of failure by a third-party service provider;

• the performance of the funds we manage;

• the affect of extensive governmental regulation;

• systems and technology risks;

• data security risks;

• third party approval of our investment products with advisors affiliated with independent broker-dealers or other networks;

• operational risks associated with the processing of investment transactions;

• changes in, or interpretation of, accounting principles or tax rules and regulations;

• fluctuations in foreign currency exchange rates; and

• retention of senior management personnel.

SEI is a savings and loan holding company subject to supervision and regulation by the Federal Reserve. SEI is not subject to specific statutory capital requirements. However, SEI is required to maintain capital that is sufficient to support the holding

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company and its subsidiaries’ business activities, and the risks inherent in those activities. To manage capital adequacy, SEI currently utilizes a target Tier 1 Leverage Ratio as defined by the Board of Governors of the Federal Reserve System.

Our principal, regulated wholly-owned subsidiaries are SEI Investments Distribution Co., or SIDCO, SEI Investments Management Corporation, or SIMC, SEI Private Trust Company, or SPTC, SEI Trust Company, or STC, and SEI Investments (Europe) Limited, or SIEL. SIDCO is a broker-dealer registered with the SEC under the Securities and Exchange Act of 1934 and is a member of the Financial Industry Regulatory Authority, Inc. (FINRA). SIMC is an investment advisor registered with the SEC under the Investment Advisers Act of 1940. SPTC is a limited purpose federal thrift chartered and regulated by the Office of the Comptroller of the Currency. STC is a Pennsylvania trust company, regulated by the Pennsylvania Department of Banking. SIEL is an investment manager and financial institution subject to regulation by the Financial Services Authority of the United Kingdom. In addition, various SEI subsidiaries are subject to the jurisdiction of regulatory authorities in Canada, the Republic of Ireland and other foreign countries. The Company has a minority ownership interest in LSV, which is also an investment advisor registered with the SEC.

The Company, its regulated subsidiaries, their regulated services and solutions and their customers are all subject to extensive legislation, regulation and supervision that recently has been subject to, and continues to experience, significant change and increased regulatory activity. These changes and regulatory activities could have a material adverse affect on us and our clients.

The various governmental agencies and self-regulatory authorities that regulate or supervise the Company and various of its subsidiaries have broad administrative powers. In the event of a failure to comply with laws, regulations and requirements of these agencies and authorities, the possible sanctions that may be imposed include the suspension of individual employees, limitations on our ability to engage in business for specified periods of time, the revocation of applicable registration as a broker-dealer, investment advisor or other regulated entity, and, as the case may be, censures and fines. Additionally, certain securities and banking laws applicable to us and our subsidiaries provide for certain private rights of action that could give rise to civil litigation. Any litigation could have significant financial and non-financial consequences including monetary judgments and the requirement to take action or limit activities that could ultimately affect our business.

Governmental scrutiny from regulators, legislative bodies and law enforcement agencies with respect to matters relating to our regulated subsidiaries and their activities, services and solutions, our business practices, our past actions and other matters has increased dramatically in the past several years. Responding to these examinations, investigations, actions and lawsuits, regardless of the ultimate outcome of the proceeding, is time consuming and expensive and can divert the time and effort of our senior management from our business. Penalties and fines sought by regulatory authorities have increased substantially over the last several years, and certain regulators have been more likely in recent years to commence enforcement actions or to advance or support legislation targeted at the financial services industry. Governmental scrutiny and legal and enforcement proceedings can also have a negative impact on our reputation and on the morale and performance of our employees, which could adversely affect our businesses and results of operations.

We are subject to the USA PATRIOT Act of 2001, which contains anti-money laundering and financial transparency laws and requires implementation of regulations applicable to financial services companies, including standards for verifying client identification and monitoring client transactions and detecting and reporting suspicious activities. Anti-money laundering laws outside the United States contain similar requirements.

We offer investment and banking solutions that also are subject to regulation by the federal and state securities and banking authorities, as well as foreign regulatory authorities, where applicable. Existing or future regulations that affect these solutions could lead to a reduction in sales of these solutions or require modifications of these solutions.

Compliance with existing and future regulations and responding to and complying with recent increased regulatory activity affecting broker-dealers, investment advisors, investment companies, financial institutions and their service providers could have a significant impact on us. We periodically undergo regulatory examinations and respond to regulatory inquiries and document requests. In addition, recent legislative activity in the United States (including the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010 and attendant rule making activities) and in other jurisdictions (including the European Union and the United Kingdom) have made and continue to make, extensive changes to the laws regulating financial services firms. As a result of these examinations, inquiries and requests, as a result of increased civil litigation activity, and as a result of these new laws and regulations, we engage legal counsel, review our compliance procedures, solution and service offerings,

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and business operations, and make changes as we deem necessary. These additional activities and required changes may result in increased expense or may reduce revenues.

Our bank clients are subject to supervision by federal and state banking authorities concerning the manner in which such clients purchase and receive our products and services. Our plan sponsor clients and our subsidiaries providing services to those clients are subject to supervision by the Department of Labor and compliance with employee benefit regulations. Investment advisor and broker-dealer clients are regulated by the SEC, state securities authorities, or FINRA. Existing or future regulations applicable to our clients may affect our clients’ purchase of our products and services.

In addition, see the discussion of governmental regulations in Item 1A “Risk Factors” in our latest Annual Report on Form 10-K for a description of the risks that proposed regulatory changes may present for our business.

Item 3. Quantitative and Qualitative Disclosures About Market Risk.

Information regarding our market risk exposures appears in Part II – Item 7A of our Annual Report on Form 10-K for the year ended December 31, 2011. There have been no material changes in our market risk exposures from those disclosed in our Annual Report on Form 10-K for 2011.

Item 4. Controls and Procedures.

(a) Evaluation of Disclosure Controls and Procedures

Our management, with the participation of our Chief Executive Officer and Chief Financial Officer, evaluated the effectiveness of our disclosure controls and procedures as of the end of the period covered by this report. Based on that evaluation, the Chief Executive Officer and Chief Financial Officer concluded that our disclosure controls and procedures as of the end of the period covered by this report are effective in ensuring that information required to be disclosed by us in reports filed under the Securities Exchange Act of 1934 is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms. Disclosure controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by an issuer in the reports that it files or submits under the Act is accumulated and communicated to the issuer’s management including its principal executive and principal financial officers, or persons performing similar functions, as appropriate to allow timely decisions regarding required disclosure. A controls system, no matter how well designed and operated, cannot provide absolute assurance that the objectives of the controls systems are met, and no evaluation of controls can provide absolute assurance that all control issues and instances of fraud, if any, within a company have been detected.

(b) Change in Internal Control over Financial Reporting

No change in our internal control over financial reporting occurred during the quarter ended March 31, 2012 that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

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PART II. OTHER INFORMATION

Item 1. 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. To date, the Complaints have been filed in the United States District Court for the Southern District of New York and in the United States District Court for the District of Maryland. The three complaints filed in the District of Maryland have been voluntarily dismissed by the plaintiffs. Two of them were subsequently re-filed in the Southern District of New York. Two of the complaints filed in the Southern District of New York have also been voluntarily dismissed by plaintiffs. 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. The Complaints allege that SIDCO is liable for these purportedly material misstatements and omissions under Section 11 of the Securities Act of 1933. The Complaints seek unspecified compensatory and other damages, reasonable costs and other relief. Defendants have moved to consolidate the complaints, which motion has been granted. The Court appointed lead plaintiff on July 13, 2010, and an amended consolidated class action complaint was filed on September 25, 2010 asserting substantially the same claims. Defendants moved to dismiss on November 15, 2010. On December 16, 2010, lead plaintiff informed the Court and Defendants that lead plaintiff elected to file a second amended consolidated complaint, which was filed on January 31, 2011. Defendants filed a motion to dismiss the second complaint on March 17, 2011. Oral argument on this motion was held on February 2, 2012. 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. 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 putative 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 have been removed to federal court, and plaintiffs’ motions to remand are pending. These two cases have been 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 and SPTC in the two remanded actions were preempted by federal law and the Court dismissed these cases with prejudice. The Court of Appeals for the Fifth Circuit granted an expedited appeal of the United States District Court’s order and judgment. The appeal was briefed, and oral argument was held on February 7, 2012. 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 April 2, 2012, SEI filed with the United States Court of Appeals for the Fifth Circuit a petition for rehearing en banc of the panel’s opinion. On April 19, 2012, the Fifth Circuit Court of Appeals denied the petition for rehearing.

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. SEI and SPTC filed exceptions in the putative 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 putative class

Page 35 of 37

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. Following the decision by the United States District Court for the Northern District of Texas, the Court in the East Baton Rouge action issued an order staying the proceedings in the East Baton Rouge class action pending the outcome of the appeal of the order and judgment of the United States District Court for the Northern District of Texas. Following the panel opinion of the Court of Appeals on March 19, 2012, the Court in the East Baton Rouge action scheduled a hearing on class certification for September 20, 2012. 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.

Because of the uncertainty of the make-up of the classes, the specific theories of liability that may survive a motion to dismiss, 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.

Item 1A. Risk Factors

Information regarding risk factors appears in Part I – Item 1A of the Company’s Annual Report on Form 10-K for the year ended December 31, 2011. There have been no material changes in our risk factors from those disclosed in our Annual Report on Form 10-K for 2011.

Item 2. Unregistered Sales of Equity Securities and Use of Proceeds.

(e) Our Board of Directors has authorized the repurchase of up to $1.928 billion worth of our common stock through multiple authorizations. Currently, there is no expiration date for our common stock repurchase program.

Information regarding the repurchase of common stock during the three months ended March 31, 2012 is as follows:

Period	Total Number of Shares Purchased		Average Price Paid per Share		Total Number of Shares Purchased as Part of Publicly Announced Program		Approximate Dollar Value of Shares that May Yet Be Purchased Under the Program
January 1 – 31, 2012		25,000	$	18.10		25,000	$	95,823,000
February 1 – 29, 2012		575,000		19.70		575,000		84,496,000
March 1 – 31, 2012		1,248,000		20.78		1,248,000		58,562,000
Total		1,848,000		20.40		1,848,000

Item 5. Other Information.

(a) On Wednesday, May 2, 2012, SEI Investments Company issued a press release announcing its financial and operating results for the first quarter ended March 31, 2012. A copy of the press release is attached as Exhibit 99.1 to this Quarterly Report on

        Form 10-Q.

Item 6. Exhibits.

The following is a list of exhibits filed as part of the Form 10-Q.

31.1	Rule 13a-15(e)/15d-15(e) Certification of Chief Executive Officer.
31.2	Rule 13a-15(e)/15d-15(e) Certification of Chief Financial Officer.
32	Section 1350 Certifications.
99.1	Press Release dated May 2, 2012 of SEI Investments Company related to the Company’s financial and operating results for the first quarter ended March 31, 2012.
101.INS	XBRL Instance Document
101.SCH	XBRL Taxonomy Extension Schema Document
101.CAL	XBRL Taxonomy Extension Calculation Linkbase Document
101.DEF	XBRL Taxonomy Extension Definition Linkbase Document
101.LAB	XBRL Taxonomy Extension Label Linkbase Document
101.PRE	XBRL Taxonomy Extension Presentation Linkbase Document

Page 36 of 37

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

		SEI INVESTMENTS COMPANY
Date:	May 3, 2012	By:	/s/ Dennis J. McGonigle
			Dennis J. McGonigle
			Chief Financial Officer

Page 37 of 37

EX-31.1

Exhibit 31.1

CERTIFICATIONS

I, Alfred P. West, Jr., certify that:

1. I have reviewed this quarterly report on Form 10-Q of SEI Investments Company;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of registrant’s board of directors (or persons performing the equivalent function):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial data and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal controls over financial reporting.

Date: May 3, 2012

/s/ Alfred P. West, Jr.

Alfred P. West, Jr.

Chairman and Chief Executive Officer

EX-31.2

Exhibit 31.2

CERTIFICATIONS

I, Dennis J. McGonigle, certify that:

1. I have reviewed this quarterly report on Form 10-Q of SEI Investments Company;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of registrant’s board of directors (or persons performing the equivalent function):

a) All significant deficiencies and material weaknesses in the design or operation of internal controls over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial data and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal controls over financial reporting.

Date: May 3, 2012

/s/ Dennis J. McGonigle

Dennis J. McGonigle

Chief Financial Officer

EX-32

Exhibit 32

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF

THE SARBANES-OXLEY ACT OF 2002

I, Alfred P. West, Jr., Chairman and Chief Executive Officer, and I, Dennis J. McGonigle, Chief Financial Officer, of SEI Investments Company, a Pennsylvania corporation (the “Company”), hereby certify that, to my knowledge:

(1) The Company’s Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2012 (the “Form 10-Q”) fully complies with the requirements of Section 13(a) of the Securities Exchange Act of 1934; and

(2) The information contained in the Form 10-Q fairly presents, in all material respects, the financial condition and results of operations of the Company.

Date: May 3, 2012	Date: May 3, 2012
/s/ Alfred P. West, Jr.	/s/ Dennis J. McGonigle
Alfred P. West, Jr.	Dennis J. McGonigle
Chairman and Chief Executive Officer	Chief Financial Officer

A signed original of this written statement required by Section 906 has been provided to the Company and will be retained by the Company and furnished to the Securities and Exchange Commission or its staff upon request.

EX-99.1

Exhibit 99.1

NEWS FROM SEI

Investor Contact:	Media Contact:
Murray Louis	Dana Grosser
SEI	SEI
+1 610-676-1932	+1 610-676-2459
mlouis@seic.com	dgrosser@seic.com
Pages: 8

FOR IMMEDIATE RELEASE

SEI REPORTS FIRST-QUARTER 2012 FINANCIAL RESULTS

OAKS, Pa., May 2, 2012 — SEI Investments Company (NASDAQ:SEIC) today announced financial results for first-quarter 2012. Diluted earnings per share were $.28 in first-quarter 2012 compared to $.31 in first-quarter 2011.

Consolidated Overview	For the Three Months
(In thousands, except earnings per share)	Ended March 31,
	2012		2011		%
Revenues	$	237,898	$	232,493		2	%
Net Income attributable to SEI		49,965		57,728		(13	%)
Diluted Earnings Per Share	$	0.28	$	0.31		(10	%)

“Strong new sales and improving revenues over fourth-quarter 2011 drove first-quarter 2012 results,” said Alfred P. West, Jr., SEI Chairman and CEO.

“Despite uncertainty in the financial markets, we are seeing buyers return to our markets. During 2012, we will continue to focus on sales results, improving productivity and service quality, and increasing profits. We are confident that the investments we are making will enable us to significantly increase shareholder value.”

1

Summary of First-Quarter Results by Business Segment

(In thousands)	For the Three Month Period
	Ended March 31,
	2012			2011			%
Private Banks:
Revenues	$	87,988		$	86,709			1	%
Expenses		87,517			82,403			6	%
Operating Profit	$	471		$	4,306			(89	%)
Operating Margin		1	%		5	%
Investment Advisors:
Revenues		49,468			48,108			3	%
Expenses		29,301			27,040			8	%
Operating Profit		20,167			21,068			(4	%)
Operating Margin		41	%		44	%
Institutional Investors:
Revenues		53,317			53,185			—
Expenses		28,100			26,953			4	%
Operating Profit		25,217			26,232			(4	%)
Operating Margin		47	%		49	%
Investment Managers:
Revenues		46,211			43,441			6	%
Expenses		30,426			27,999			9	%
Operating Profit		15,785			15,442			2	%
Operating Margin		34	%		36	%
Investments in New Businesses:
Revenues		914			1,050			(13	%)
Expenses		3,698			3,125			18	%
Operating Loss		(2,784	)		(2,075	)		34	%
Operating Margin		N/A			N/A
Totals:
Revenues	$	237,898		$	232,493			2	%
Expenses		179,042			167,520			7	%
Corporate overhead expenses		11,082			10,648			4	%
Noncontrolling interest reflected in segments		(315	)		(272	)		N/A
Income from operations	$	48,089		$	54,597			(12	%)

2

First-Quarter Business Commentary:

• Revenues increased in first-quarter 2012 as compared to first-quarter 2011 and to fourth-quarter 2011 due to an increase in Asset management, administrative, and distribution fee revenues from improved cash-flows and market appreciation in first-quarter 2012. Our average assets under management, excluding LSV, increased $9.6 billion, or eight percent, to $124.1 billion in the first-quarter 2012 as compared to $114.5 billion during the first-quarter 2011 (See attached Ending and Average Asset Balances schedules for further details).

• Sales events, net of client losses, during first-quarter 2012 totaled approximately $26.1 million and are expected to generate net annualized recurring revenues of approximately $23.5 million when contract values are fully realized. These sales events resulted in an increase in sales compensation expense when compared to first-quarter 2011 of $1.8 million.

• Total consolidated expenses in first-quarter 2012 include approximately an additional $1.8 million in fees for other asset management distribution costs and employee severance costs.

• Net income attributable to SEI includes gains from SIV securities of $2.9 million in first-quarter 2012 compared to gains of $6.9 million in first-quarter 2011.

• The effective tax rates were 37.2 percent in the first-quarter 2012, 37.1 percent in the first-quarter 2011 and 34.7 percent in the fourth-quarter 2011. The increase in the tax rate in the first-quarter 2012 as compared to the fourth-quarter 2011 was due to the expiration of the research and development tax credit in first-quarter 2012 and tax planning strategies which benefited the tax rate in fourth-quarter 2011.

• In the first-quarter 2012, SEI purchased 1.8 million shares of its common stock for $37.7 million.

3

Earnings Conference Call

A conference call to review earnings is scheduled for 2:00 PM ET on May 2, 2012. Investors may listen to the call at www.seic.com/investors or listen at www.earnings.com, a service of Thomson Streetevents. The call may also be accessed at numerous financial services web sites including AOL and Yahoo. Investors may also listen to replays at these web sites, or by telephone at (USA) 1-877-777-1972; (International) 612-332-0636, access code 245414.

About SEI

SEI (NASDAQ:SEIC) is a leading global provider of investment processing, fund processing, and investment management business outsourcing solutions that help corporations, financial institutions, financial advisors, and ultra-high-net-worth families create and manage wealth. As of March 31, 2012, through its subsidiaries and partnerships in which the company has a significant interest, SEI manages or administers $428 billion in mutual fund and pooled or separately managed assets, including $189 billion in assets under management and $239 billion in client assets under administration. For more information, visit www.seic.com.

Many of the statements in this release may be considered “forward looking statements” and include discussions about future operations, strategies and financial results. Forward-looking statements are based upon estimates and assumptions that involve risks and uncertainties, many of which are beyond our control or are subject to change. Although we believe our assumptions are reasonable, they could be inaccurate. Our actual future revenues and income could differ materially from our expected results. We have no obligation to publicly update or revise any forward-looking statements.

4

SEI INVESTMENTS COMPANY

CONSOLIDATED STATEMENTS OF OPERATIONS

(In thousands, except per share data)

(Unaudited)

	Three Months Ended March 31,
	2012			2011
Asset management, admin. and distribution fees	$	172,954		$	167,504
Information processing and software servicing fees		56,200			55,824
Transaction–based and trade execution fees		8,744			9,165
Total revenues		237,898			232,493
Subadvisory, distribution and other asset mgmt costs		28,467			26,296
Software royalties and other information processing costs		6,477			7,017
Brokerage commissions		6,307			6,581
Compensation, benefits and other personnel		78,543			71,025
Stock-based compensation		4,033			3,732
Consulting, outsourcing and professional fees		26,955			25,998
Data processing and computer related		11,465			11,303
Facilities, supplies and other costs		14,508			14,102
Amortization		7,622			6,231
Depreciation		5,432			5,611
Total expenses		189,809			177,896
Income from operations		48,089			54,597
Net gain on investments		3,205			7,278
Interest and dividend income		1,487			1,544
Interest expense		(161	)		(204	)
Equity in earnings of unconsolidated affiliate		27,330			28,949
Net income before income taxes		79,950			92,164
Income taxes		29,715			34,124
Net income		50,235			58,040
Less: Net income attributable to the noncontrolling interest		(270	)		(312	)
Net income attributable to SEI	$	49,965		$	57,728
Diluted earnings per common share	$	0.28		$	0.31
Shares used to calculate diluted earnings per common share		177,668			188,495
Basic earnings per common share	$	0.28		$	0.31
Shares used to calculate basic earnings per common share		176,348			185,787

5

SEI INVESTMENTS COMPANY

CONDENSED BALANCE SHEETS

(In thousands)

(Unaudited)

	March 31, 2012		December 31, 2011
Assets
Cash and short-term investments	$	388,127	$	420,986
Restricted cash		6,000		6,000
Receivables, net		182,093		167,909
Securities owned		21,053		20,949
Other current assets		20,066		19,107
Total current assets		617,339		634,951
Property and equipment, net		136,431		129,548
Marketable securities		140,675		139,333
Capitalized software, net		311,229		309,133
Investment in unconsolidated affiliate		66,691		60,954
Other assets, net		21,261		20,640
Total assets	$	1,293,626	$	1,294,559
Liabilities
Current liabilities	$	118,877	$	151,073
Deferred income taxes		92,477		93,751
Other Long-term liabilities		10,832		8,276
Total SEI Investments Company shareholders’ equity		1,054,544		1,025,316
Noncontrolling interest		16,896		16,143
Total Equity		1,071,440		1,041,459
Total liabilities and equity	$	1,293,626	$	1,294,559

6

SEI INVESTMENTS COMPANY

ENDING ASSET BALANCES

(In millions)

(Unaudited)

	Mar. 31, 2011		Jun. 30, 2011		Sept. 30, 2011		Dec. 31, 2011		Mar. 31, 2012
Private Banks:
Equity/Fixed Income prgms.	$	14,809	$	16,720	$	15,442	$	16,435	$	17,180
Collective Trust Fund prgms.		576		504		476		450		435
Liquidity funds		5,217		4,918		5,529		5,553		5,549
Total assets under mgmt.	$	20,602	$	22,142	$	21,447	$	22,438	$	23,164
Client assets under admin.		11,227		10,994		9,845		10,355		10,916
Total assets	$	31,829	$	33,136	$	31,292	$	32,793	$	34,080
Investment Advisors:
Equity/Fixed Income prgms.	$	28,296	$	28,410	$	24,757	$	26,639	$	29,722
Collective Trust Fund prgms.		1,618		1,499		1,392		1,298		1,199
Liquidity funds		1,551		1,651		2,653		2,505		1,643
Total assets under mgmt.	$	31,465	$	31,560	$	28,802	$	30,442	$	32,564
Institutional Investors:
Equity/Fixed Income prgms.	$	51,287	$	51,180	$	46,259	$	49,051	$	54,537
Collective Trust Fund prgms.		608		482		510		492		424
Liquidity funds		3,202		3,146		3,356		3,888		3,725
Total assets under mgmt.	$	55,097	$	54,808	$	50,125	$	53,431	$	58,686
Investment Managers:
Equity/Fixed Income prgms.	$	37	$	50	$	64	$	57	$	62
Collective Trust Fund prgms.		8,841		10,372		10,896		11,255		12,781
Liquidity funds		139		179		195		152		147
Total assets under mgmt.	$	9,017	$	10,601	$	11,155	$	11,464	$	12,990
Client assets under admin. (A)		238,335		238,432		223,620		221,198		228,327
Total assets	$	247,352	$	249,033	$	234,775	$	232,662	$	241,317
Investments in New Businesses:
Equity/Fixed Income prgms.	$	598	$	558	$	490	$	515	$	568
Liquidity funds		56		41		41		37		34
Total assets under mgmt.	$	654	$	599	$	531	$	552	$	602
LSV Asset Management
Equity/Fixed Income prgms.	$	62,370	$	60,626	$	49,444	$	53,712	$	60,607
Consolidated:
Equity/Fixed Income prgms (B)	$	157,397	$	157,544	$	136,456	$	146,409	$	162,676
Collective Trust Fund prgms.		11,643		12,857		13,274		13,495		14,839
Liquidity funds		10,165		9,935		11,774		12,135		11,098
Total assets under mgmt.	$	179,205	$	180,336	$	161,504	$	172,039	$	188,613
Client assets under admin. (C)		249,562		249,426		233,465		231,553		239,243
Total assets	$	428,767	$	429,762	$	394,969	$	403,592	$	427,856

(A) Client assets under administration in the Investment Managers segment include $38.5 billion of assets balances that require limited services and therefore are at fee levels below our normal full service assets (as of March 31, 2012).

(B) Equity/Fixed Income programs include $2.6 billion of assets invested in various asset allocation funds at March 31, 2012.

(C) In addition to the numbers presented, SEI also administers an additional $4.6 billion in Funds of Funds assets (as of March 31, 2012) on which SEI does not earn an administration fee.

7

SEI INVESTMENTS COMPANY

AVERAGE ASSET BALANCES

(In millions)

(Unaudited)

	1st Qtr 2011		2nd Qtr 2011		3rd Qtr 2011		4th Qtr 2011		1st Qtr 2012
Private Banks:
Equity/Fixed Income prgms.	$	14,170	$	16,176	$	16,592	$	16,624	$	17,116
Collective Trust Fund prgms.		593		543		505		464		436
Liquidity funds		5,058		4,909		5,210		5,401		5,581
Total assets under mgmt.	$	19,821	$	21,628	$	22,307	$	22,489	$	23,133
Client assets under admin.		10,921		11,114		10,364		10,290		10,211
Total assets	$	30,742	$	32,742	$	32,671	$	32,779	$	33,344
Investment Advisors:
Equity/Fixed Income prgms.	$	27,841	$	28,502	$	26,658	$	26,094	$	28,426
Collective Trust Fund prgms.		1,687		1,544		1,442		1,314		1,238
Liquidity funds		1,580		1,576		2,224		2,499		2,015
Total assets under mgmt.	$	31,108	$	31,622	$	30,324	$	29,907	$	31,679
Institutional Investors:
Equity/Fixed Income prgms.	$	50,392	$	51,567	$	49,115	$	48,504	$	52,270
Collective Trust Fund prgms.		608		554		505		500		427
Liquidity funds		3,418		3,515		3,416		3,461		3,765
Total assets under mgmt.	$	54,418	$	55,636	$	53,036	$	52,465	$	56,462
Investment Managers:
Equity/Fixed Income prgms.	$	1	$	38	$	52	$	65	$	58
Collective Trust Fund prgms.		8,288		9,560		11,292		10,773		11,983
Liquidity funds		210		165		200		219		190
Total assets under mgmt.	$	8,499	$	9,763	$	11,544	$	11,057	$	12,231
Client assets under admin.		237,376		241,423		236,953		224,633		224,547
Total assets	$	245,875	$	251,186	$	248,497	$	235,690	$	236,778
Investments in New Businesses:
Equity/Fixed Income prgms.	$	579	$	561	$	525	$	515	$	549
Liquidity funds		61		42		42		42		39
Total assets under mgmt.	$	640	$	603	$	567	$	557	$	588
LSV Asset Management
Equity/Fixed Income prgms.	$	62,212	$	63,000	$	54,679	$	54,021	$	59,200
Consolidated:
Equity/Fixed Income prgms	$	155,195	$	159,844	$	147,621	$	145,823	$	157,619
Collective Trust Fund prgms.		11,176		12,201		13,744		13,051		14,084
Liquidity funds		10,327		10,207		11,092		11,622		11,590
Total assets under mgmt.	$	176,698	$	182,252	$	172,457	$	170,496	$	183,293
Client assets under admin.		248,297		252,537		247,317		234,923		234,758
Total assets	$	424,995	$	434,789	$	419,774	$	405,419	$	418,051

8

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Fair Value Measurements (Narrative) (Details) (Significant Unobservable Inputs (Level 3) [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial liabilities	$ 0	$ 0

XML

Income Taxes (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Income Taxes [Abstract]
Gross liability for unrecognized tax benefits, exclusive of interest and penalties	$ 11,757		$ 9,410
Unrecognized tax benefits that would affect effective tax rate	10,043		8,320
Interest and penalties on unrecognized benefits	843		634
Effective tax rates	37.20%	37.10%
Unrecognized tax benefits within the next twelve months	$ 1,768

XML

Shareholders' Equity (Schedule Of Recognition Of Compensation Cost) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-Based Compensation Expense	$ 45,594
Remainder Of 2012 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-Based Compensation Expense	11,837
2013 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-Based Compensation Expense	12,715
2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-Based Compensation Expense	12,521
2015 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-Based Compensation Expense	3,850
2016 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-Based Compensation Expense	2,358
2017 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-Based Compensation Expense	$ 2,313

XML

Income Taxes (Interest And Penalties) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Income Taxes [Abstract]
Gross liability for unrecognized tax benefits, exclusive of interest and penalties	$ 11,757	$ 9,410
Interest and penalties on unrecognized benefits	843	634
Total gross uncertain tax positions	12,600	10,044
Amount included in Current liabilities	1,768	1,768
Amount included in Other long-term liabilities	10,832	8,276
Gross uncertain tax positions	$ 12,600	$ 10,044

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Shareholders' Equity (Narrative) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 45,594
Total intrinsic value of options exercised	3,752
Aggregate intrinsic value of options exercisable	36,218
Market value of common stock	$ 20.69
Weighted average exercise price per share	$ 17.36
Total options that were outstanding	26,082,000
Total options that were exercisable	10,873,000
Shares purchased and retired	1,848,000
Company purchased, cost	37,714
Remaining stock repurchase authorization amount	$ 58,562
2007 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of active equity compensation plans	1
Options available for grant	20,000,000
Percentage of stock options vested when specified diluted earnings per share targets are achieved	50.00%
Remaining percentage of stock options vested when secondary, higher specified diluted earnings per share targets are achieved	50.00%

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Investment In Unconsolidated Affiliate (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				1 Months Ended		3 Months Ended	1 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011	Mar. 31, 2012 LSV [Member]	Apr. 30, 2012 LSV Employee Group II [Member]	Apr. 30, 2011 LSV Employee Group II [Member]	Mar. 31, 2012 LSV Employee Group II [Member]	Apr. 30, 2011 Bank Of America [Member] LSV Employee Group II [Member]
Investments in and Advances to Affiliates [Line Items]
Equity method investment, ownership percentage				41.00%
Total investment in LSV	$ 66,691		$ 60,954
Investment in LSV in excess of the underlying equity in net assets	3,608
Partnership distribution payments received from LSV	21,593	23,802
Variable interest entity, principal payment					249		219
Variable interest entity, unpaid principal balance of the term loan					2,729		2,978
Proportionate share in earnings of LSV	27,330	28,949
Amount financed through new term loan								3,655
Purchase partnership interest						4,300
Goodwill				$ 3,062
Maturity of term loan, years							P4Y

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Marketable Securities (Tables)

3 Months Ended

Mar. 31, 2012

Marketable Securities [Abstract]

Investments Available For Sale

	As of March 31, 2012
	Cost Amount		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
SEI-sponsored mutual funds	$	12,744	$	84	$	(13	)	$	12,815
Other mutual funds		28		4		0			32
Debt securities		67,407		3,960		0			71,367
	$	80,179	$	4,048	$	(13	)	$	84,214

	As of December 31, 2011
	Cost Amount		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
SEI-sponsored mutual funds	$	8,243	$	48	$	(360	)	$	7,931
Other mutual funds		69		10		0			79
Debt securities		70,604		4,394		0			74,998
	$	78,916	$	4,452	$	(360	)	$	83,008

Trading Securities

	As of March 31, 2012
	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Fair Value
SIV securities	$	143,096	$	0	$	(92,073	)	$	51,023
LSV-sponsored mutual funds		2,049		2,171		0			4,220
Other investments		1,215		3		0			1,218
	$	146,360	$	2,174	$	(92,073	)	$	56,461

	As of December 31, 2011
	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Fair Value
SIV securities	$	146,363	$	0	$	(94,955	)	$	51,408
LSV-sponsored mutual funds		2,049		1,653		0			3,702
Other investments		1,215		0		0			1,215
	$	149,627	$	1,653	$	(94,955	)	$	56,325

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Accumulated Comprehensive Income (Loss) (Schedule Of Accumulated Other Comprehensive Income (Loss), Net Of Tax) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income (loss), Foreign Currency Translation Adjustments	$ 1,546		$ (674)
Accumulated other comprehensive income (loss), Unrealized Holding Gains (Losses) on Investments	2,545		2,574
Accumulated Other Comprehensive Income (Loss)	4,091		1,900
Total comprehensive loss, Foreign Currency Translation Adjustments	2,703	2,828
Total comprehensive income (loss)	2,674	2,555
Total comprehensive loss attributable to noncontrolling interest, Foreign Currency Translation Adjustments	483	420
Total comprehensive income attributable to SEI Investments Company, Foreign Currency Translation Adjustments	2,220
Total comprehensive (loss) attributable to SEI Investments Company, Unrealized Holding Gains (Losses) on Investments	(29)
Total comprehensive income attributable to SEI Investments Company	2,191
SEI Investments Company [Member]
Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income (loss), Foreign Currency Translation Adjustments	660		(2,043)
Accumulated other comprehensive income (loss), Unrealized Holding Gains (Losses) on Investments	2,545		2,574
Accumulated Other Comprehensive Income (Loss)	3,205		531
Total comprehensive loss, Foreign Currency Translation Adjustments	2,703
Total comprehensive loss, Unrealized Holding Gains (Losses) on Investments	(29)
Total comprehensive income (loss)	2,674
Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income (loss), Foreign Currency Translation Adjustments	886		1,369
Accumulated other comprehensive income (loss), Unrealized Holding Gains (Losses) on Investments	0		0
Accumulated Other Comprehensive Income (Loss)	886		1,369
Total comprehensive loss attributable to noncontrolling interest, Foreign Currency Translation Adjustments	(483)
Total comprehensive income attributable to noncontrolling interest, Unrealized Holding Gains (Losses) on Investments	0
Total comprehensive loss attributable to noncontrolling interest	$ (483)

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Marketable Securities (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Net unrealized holding gains	$ 2,545		$ 2,574
Unrealized holding gains during the period, income tax expense	1,490		1,518
Net gain (loss) from investments	3,205	7,278
Securities owned	21,053		20,949
SEI Private Trust Company [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt maturity, minimum	2020
Debt maturity, maximum	2041
U.S. Government Agency And Commercial Paper Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Debt maturity, maximum	P1Y
SIV Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Net gains from SIV securities	2,882	6,864
Gains from cash payments received from SIV securities	2,111	2,049
Gains or losses from increase/decrease in fair value of SIV securities	$ 771	$ 4,815

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Composition Of Certain Financial Statement Captions (Property And Equipment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Composition Of Certain Financial Statement Captions [Abstract]
Buildings	$ 137,327		$ 136,949
Equipment	63,350		64,256
Land	9,929		9,929
Purchased software	89,262		77,971
Furniture and fixtures	18,222		17,999
Leasehold improvements	4,743		4,558
Construction in progress	108		339
Property and Equipment, gross	322,941		312,001
Less: Accumulated depreciation	(186,510)		(182,453)
Property and Equipment, net	136,431		129,548
Depreciation expense	$ 5,432	$ 5,611

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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	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Business Segment Information [Abstract]
Total operating profit from segments above	$ 58,856	$ 64,973
Corporate overhead expenses	(11,082)	(10,648)
Noncontrolling interest reflected in segments	315	272
Income from operations	$ 48,089	$ 54,597

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Shareholders' Equity (Stock-Based Compensation Expense) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Shareholders' Equity [Abstract]
Stock-based compensation expense	$ 4,033	$ 3,732
Less: Deferred tax benefit	(1,521)	(1,398)
Stock-based compensation expense, net of tax	$ 2,512	$ 2,334

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Investment In Unconsolidated Affiliate

3 Months Ended

Mar. 31, 2012

Investment In Unconsolidated Affiliate [Abstract]

Investment In Unconsolidated Affiliate

Note 2. Investment in Unconsolidated Affiliate

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 small number of SEI-sponsored mutual funds. As of March 31, 2012, the Company's total partnership interest in LSV was approximately 41 percent. 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 affiliate on the accompanying Consolidated Balance Sheets and its interest in the earnings of LSV is reflected in Equity in earnings of unconsolidated affiliate on the accompanying Consolidated Statements of Operations.

At March 31, 2012, the Company's total investment in LSV was $66,691. The investment in LSV exceeded the underlying equity in the net assets of LSV by $3,608, of which $3,062 is considered goodwill embedded in the investment. The Company receives partnership distributions from LSV on a quarterly basis. The Company received partnership distribution payments from LSV for $21,593 and $23,802 in the three months ended March 31, 2012 and 2011, respectively.

The Company's proportionate share in the earnings of LSV was $27,330 and $28,949 during the three months ended March 31, 2012 and 2011, respectively.

The following table contains the condensed statements of operations of LSV for the three months ended March 31, 2012 and 2011:

	Three Months Ended March 31,
	2012		2011
Revenues	$	77,465	$	79,402
Net income		66,673		69,946

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 to slightly under 40 percent.

Guaranty Agreement

In April 2011, LSV Employee Group II, LLC agreed to purchase a partnership interest of an existing LSV employee for $4,300, of which $3,655 was financed through a term loan with Bank of America, N.A. (Bank of America). The Company provided an unsecured guaranty to the lenders of all the obligations of LSV Employee Group II, LLC. The lenders have the right to seek payment from the Company in the event of a default by LSV Employee Group II, LLC. 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 $219 during the three months ended March 31, 2012. As of March 31, 2012, the remaining unpaid principal balance of the term loan was $2,978. This amount is not reflected, nor is it required to be reflected, in the Company's Consolidated Balance Sheet at March 31, 2012.

The Company's direct interest in LSV is unchanged as a result of this transaction. The Company has determined that LSV Employee Group II is a variable interest entity (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.

In April 2012, LSV Employee Group II made a principal payment of $249. As of April 30, 2012, the remaining unpaid principal balance of the term loan was $2,729. 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.

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Marketable Securities (Investments Available For Sale) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Investment Available for Sale, Cost Amount	$ 80,179	$ 78,916
Investment Available for Sale, Gross Unrealized Gains	4,048	4,452
Investment Available for Sale, Gross Unrealized Losses	(13)	(360)
Investment Available for Sale, Fair Value	84,214	83,008
SEI-Sponsored Mutual Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment Available for Sale, Cost Amount	12,744	8,243
Investment Available for Sale, Gross Unrealized Gains	84	48
Investment Available for Sale, Gross Unrealized Losses	(13)	(360)
Investment Available for Sale, Fair Value	12,815	7,931
Other Mutual Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment Available for Sale, Cost Amount	28	69
Investment Available for Sale, Gross Unrealized Gains	4	10
Investment Available for Sale, Gross Unrealized Losses	0	0
Investment Available for Sale, Fair Value	32	79
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment Available for Sale, Cost Amount	67,407	70,604
Investment Available for Sale, Gross Unrealized Gains	3,960	4,394
Investment Available for Sale, Gross Unrealized Losses	0	0
Investment Available for Sale, Fair Value	$ 71,367	$ 74,998

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Income Taxes (Tables)

3 Months Ended

Mar. 31, 2012

Income Taxes [Abstract]

Schedule Of Interest And Penalties

	March 31, 2012		December 31, 2011
Gross liability for unrecognized tax benefits, exclusive of interest and penalties	$	11,757	$	9,410
Interest and penalties on unrecognized benefits		843		634
Total gross uncertain tax positions	$	12,600	$	10,044
Amount included in Current liabilities	$	1,768	$	1,768
Amount included in Other long-term liabilities		10,832		8,276
	$	12,600	$	10,044

XML

Business Segment Information (Tables)

3 Months Ended

Mar. 31, 2012

Business Segment Information [Abstract]

Schedule Of Financial Information About Business Segments

	Private Banks			Investment Advisors			Institutional Investors			Investment Managers			Investments In New Businesses			Total
	For the Three Months Ended March 31, 2012
Revenues	$	87,988		$	49,468		$	53,317		$	46,211		$	914		$	237,898
Expenses		87,517			29,301			28,100			30,426			3,698			179,042
Operating profit (loss)	$	471		$	20,167		$	25,217		$	15,785		$	(2,784	)	$	58,856
Operating margin		1	%		41	%		47	%		34	%		N/A			25	%

	Private Banks			Investment Advisors			Institutional Investors			Investment Managers			Investments In New Businesses			Total
	For the Three Months Ended March 31, 2011
Revenues	$	86,709		$	48,108		$	53,185		$	43,441		$	1,050		$	232,493
Expenses		82,403			27,040			26,953			27,999			3,125			167,520
Operating profit (loss)	$	4,306		$	21,068		$	26,232		$	15,442		$	(2,075	)	$	64,973
Operating margin		5	%		44	%		49	%		36	%		N/A			28	%

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

	2012			2011
Total operating profit from segments above	$	58,856		$	64,973
Corporate overhead expenses		(11,082	)		(10,648	)
Noncontrolling interest reflected in segments		315			272
Income from operations	$	48,089		$	54,597

Schedule Of Additional Information Pertaining To Business Segments

	Capital Expenditures				Depreciation
	2012		2011		2012		2011
Private Banks	$	11,842	$	11,030	$	3,728	$	4,038
Investment Advisors		4,141		3,742		494		591
Institutional Investors		1,231		881		262		292
Investment Managers		3,053		1,784		476		503
Investments in New Businesses		272		212		334		30
Total from business segments	$	20,539	$	17,649	$	5,294	$	5,454
Corporate Overhead		854		374		138		157
	$	21,393	$	18,023	$	5,432	$	5,611

	Amortization
	2012		2011
Private Banks	$	4,685	$	4,229
Investment Advisors		1,716		1,418
Institutional Investors		302		167
Investment Managers		201		115
Investments in New Businesses		277		59
Total from business segments	$	7,181	$	5,988
Corporate Overhead		441		243
	$	7,622	$	6,231

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Marketable Securities (Trading Securities) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2012	Dec. 31, 2011
Gain (Loss) on Investments [Line Items]
Trading Securities, Cost	$ 146,360	$ 149,627
Trading Securities, Gross Unrealized Gains	2,174	1,653
Trading Securities, Gross Unrealized Losses	(92,073)	(94,955)
Trading Securities, Fair Value	56,461	56,325
SIV Securities [Member]
Gain (Loss) on Investments [Line Items]
Trading Securities, Cost	143,096	146,363
Trading Securities, Gross Unrealized Gains	0	0
Trading Securities, Gross Unrealized Losses	(92,073)	(94,955)
Trading Securities, Fair Value	51,023	51,408
LSV-Sponsored Mutual Funds [Member]
Gain (Loss) on Investments [Line Items]
Trading Securities, Cost	2,049	2,049
Trading Securities, Gross Unrealized Gains	2,171	1,653
Trading Securities, Gross Unrealized Losses	0	0
Trading Securities, Fair Value	4,220	3,702
Other Investments [Member]
Gain (Loss) on Investments [Line Items]
Trading Securities, Cost	1,215	1,215
Trading Securities, Gross Unrealized Gains	3	0
Trading Securities, Gross Unrealized Losses	0	0
Trading Securities, Fair Value	$ 1,218	$ 1,215

XML

Summary Of Significant Accounting Policies (Narrative) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 Y	Mar. 31, 2011	Dec. 31, 2011	Dec. 31, 2010
Cash and cash equivalents	$ 388,127	$ 498,039	$ 420,986	$ 496,292
Capitalized software development costs	9,277	10,655
Capitalized software, weighted average remaining life, years	10.3
Amortization expense related to capitalized software	7,181	5,981
Capitalized software, accumulated amortization	124,281		117,100
Anti-dilutive employee stock options	14,329,000	7,609,000
Average exercise price of anti-dilutive employee stock options	$ 23.43	$ 28.26
SEI Investments (Europe) Limited [Member]
Restricted cash	5,000		5,000
SEI Investments Distribution Co. (SIDCO) [Member]
Restricted cash	1,000		1,000
Global Wealth Platform [Member]
Capitalized software, weighted average remaining life, years	10.3
Amortization expense related to capitalized software	7,064	5,840
Net book value of GWP	289,623
Capitalized software, accumulated amortization	94,826
Capitalized software development costs in-progress associated with future releases	20,830
Software useful life, years	15
SEI-Sponsored Open-Ended Money Market Mutual Funds [Member]
Cash and cash equivalents	$ 224,019		$ 281,760

XML

Summary Of Significant Accounting Policies (Calculation Of Basic And Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Summary Of Significant Accounting Policies [Abstract]
Basic earnings per common share, Income (Numerator)	$ 49,965	$ 57,728
Basic earnings per common share, Shares (Denominator)	176,348	185,787
Basic earnings per common share, Per Share Amount	$ 0.28	$ 0.31
Dilutive effect of stock options, Income (Numerator)	0	0
Dilutive effect of stock options, Shares (Denominator)	1,320	2,708
Diluted earnings per common share, Income (Numerator)	$ 49,965	$ 57,728
Diluted earnings per common share, Shares (Denominator)	177,668	188,495
Diluted earnings per common share, Per Share Amount	$ 0.28	$ 0.31

XML

Summary Of Significant Accounting Policies

3 Months Ended

Mar. 31, 2012

Summary Of Significant Accounting Policies [Abstract]

Summary Of Significant Accounting Policies

Note 1. 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.

Basis of Presentation

The accompanying Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States of America. Certain financial information and accompanying note disclosure normally included in the Company's Annual Report on Form 10-K has been condensed or omitted. The interim financial information is unaudited but reflects all adjustments (consisting of only normal recurring adjustments) which are, in the opinion of management, necessary for a fair statement of financial position of the Company as of March 31, 2012, the results of operations for the three months ended March 31, 2012 and 2011, and cash flows for the three month periods ended March 31, 2012 and 2011. These interim Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and the Notes to the Consolidated Financial Statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2011.

There have been no significant changes in significant accounting policies during the three months ended March 31, 2012 as compared to the significant accounting policies described in the Company's Annual Report on Form 10-K for the year ended December 31, 2011.

Cash and Cash Equivalents

Cash and cash equivalents includes $224,019 and $281,760 at March 31, 2012 and December 31, 2011, respectively, primarily invested in SEI-sponsored open-ended money market mutual funds.

Restricted Cash

Restricted cash includes $5,000 at March 31, 2012 and December 31, 2011 segregated for regulatory purposes related to trade-execution services conducted by SEI Investments (Europe) Limited. Restricted cash also includes $1,000 at March 31, 2012 and December 31, 2011 segregated in special reserve accounts for the benefit of customers of the Company's broker-dealer subsidiary, SEI Investments Distribution Co. (SIDCO), in accordance with certain rules established by the Securities and Exchange Commission for broker-dealers.

Capitalized

Software

The Company capitalized $9,277 and $10,655 of software development costs during the three months ended March 31, 2012 and 2011, respectively. As of March 31, 2012, capitalized software placed into service included on the accompanying Consolidated Balance Sheet had a weighted average remaining life of approximately 10.3 years. Amortization expense related to capitalized software was $7,181 and $5,981 during the three months ended March 31, 2012 and 2011, respectively.

Software development costs capitalized during the three months ended March 31, 2012 and 2011 relates to the continued development of the Global Wealth Platform (GWP). As of March 31, 2012, the net book value of GWP was $289,623, net of accumulated amortization of $94,826. Capitalized software development costs in-progress at March 31, 2012 associated with future releases to GWP were $20,830. GWP has an estimated useful life of 15 years and a weighted average remaining life of 10.3 years. Amortization expense for GWP was $7,064 and $5,840 during the three months ended March 31, 2012 and 2011, respectively.

Earnings per Share

The calculations of basic and diluted earnings per share for the three months ended March 31, 2012 and 2011 are:

		000,000		000,000		000,000
	For the Three Month Period Ended March 31, 2012
	Income (Numerator)		Shares (Denominator)		Per Share Amount
Basic earnings per common share	$	49,965		176,348	$	.28
Dilutive effect of stock options		0		1,320
Diluted earnings per common share	$	49,965		177,668	$	.28

		000,000		000,000		000,000
	For the Three Month Period Ended March 31, 2011
	Income (Numerator)		Shares (Denominator)		Per Share Amount
Basic earnings per common share	$	57,728		185,787	$	.31
Dilutive effect of stock options		0		2,708
Diluted earnings per common share	$	57,728		188,495	$	.31

Employee stock options to purchase 14,329,000 and 7,609,000 shares of common stock, with an average exercise price of $23.43 and $28.26, were outstanding during the three month periods ended March 31, 2012 and 2011, respectively, but not included in the computation of diluted earnings per common share because the effect on diluted earnings per common share would have been anti-dilutive.

Statements of Cash Flows

For purposes of the Consolidated Statements of Cash Flows, the Company considers investment instruments purchased with an original maturity of three months or less to be cash equivalents.

The following table provides the details of the adjustments to reconcile net income to net cash provided by operating activities for the three months ended March 31:

	2012			2011
Net income	$	50,235		$	58,040
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation		5,432			5,611
Amortization		7,622			6,231
Equity in earnings of unconsolidated affiliate		(27,330	)		(28,949	)
Distributions received from unconsolidated affiliate		21,593			23,802
Stock-based compensation		4,033			3,732
Provision for losses on receivables		(48	)		(236	)
Deferred income tax expense		(517	)		2,345
Net realized gains from investments		(3,205	)		(7,278	)
Change in other long-term liabilities		2,556			294
Change in other assets		(1,385	)		(1,841	)
Other		2,656			3,036
Change in current asset and liabilities
Decrease (increase) in
Receivables from regulated investment companies		(9,183	)		824
Receivables		(4,413	)		(3,551	)
Other current assets		(1,687	)		(1,210	)
Increase (decrease) in
Accounts payable		242			(1,841	)
Accrued liabilities		(6,575	)		(151	)
Deferred revenue		(802	)		(522	)
Total adjustments		(11,011	)		296
Net cash provided by operating activities	$	39,224		$	58,336

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Summary Of Significant Accounting Policies (Adjustments To Reconcile Net Income To Net Cash Provided By Operating Activities) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Summary Of Significant Accounting Policies [Abstract]
Net income	$ 50,235	$ 58,040
Depreciation	5,432	5,611
Amortization	7,622	6,231
Equity in earnings of unconsolidated affiliate	(27,330)	(28,949)
Distributions received from unconsolidated affiliate	21,593	23,802
Stock-based compensation	4,033	3,732
Provision for losses on receivables	(48)	(236)
Deferred income tax expense	(517)	2,345
Net realized gains from investments	(3,205)	(7,278)
Change in other long-term liabilities	2,556	294
Change in other assets	(1,385)	(1,841)
Other	2,656	3,036
Decrease (increase) in receivables from regulated investment companies	(9,183)	824
Decrease (increase) in Receivables	(4,413)	(3,551)
Decrease (increase) in Other current assets	(1,687)	(1,210)
Increase (decrease) in Accounts payable	242	(1,841)
Increase (decrease) in Accrued liabilities	(6,575)	(151)
Increase (decrease) in Deferred revenue	(802)	(522)
Total adjustments	(11,011)	296
Net cash provided by operating activities	$ 39,224	$ 58,336

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Fair Value Measurements (Fair Value Of Certain Financial Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity available-for-sale securities	$ 12,847	$ 8,010
Fixed income available-for-sale securities	71,367	74,998
Fixed income securities owned	21,053	20,949
Trading securities	56,461	56,325
Assets, fair value	161,728	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	12,847	8,010
Fixed income available-for-sale securities	0	0
Fixed income securities owned	0	0
Trading securities	4,220	3,702
Assets, fair value	17,067	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	71,367	74,998
Fixed income securities owned	21,053	20,949
Trading securities	0	0
Assets, fair value	92,420	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	52,241	52,623
Assets, fair value	$ 52,241	$ 52,623

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Business Segment Information (Schedule Of Additional Information Pertaining To Business Segments) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Segment Reporting Information [Line Items]
Capital Expenditures	$ 21,393	$ 18,023
Depreciation	5,432	5,611
Amortization	7,622	6,231
Private Banks [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	11,842	11,030
Depreciation	3,728	4,038
Amortization	4,685	4,229
Investment Advisors [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	4,141	3,742
Depreciation	494	591
Amortization	1,716	1,418
Institutional Investors [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	1,231	881
Depreciation	262	292
Amortization	302	167
Investment Managers [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	3,053	1,784
Depreciation	476	503
Amortization	201	115
Investments In New Businesses [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	272	212
Depreciation	334	30
Amortization	277	59
Total From Business Segments [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	20,539	17,649
Depreciation	5,294	5,454
Amortization	7,181	5,988
Corporate Overhead [Member]
Segment Reporting Information [Line Items]
Capital Expenditures	854	374
Depreciation	138	157
Amortization	$ 441	$ 243

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Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Current Assets:
Cash and cash equivalents	$ 388,127	$ 420,986
Restricted cash	6,000	6,000
Receivables from regulated investment companies	34,983	25,800
Receivables, net of allowance for doubtful accounts of $876 and $924 (Note 4)	147,110	142,109
Deferred income taxes	422	1,150
Securities owned (Note 6)	21,053	20,949
Other current assets	19,644	17,957
Total Current Assets	617,339	634,951
Property and Equipment, net of accumulated depreciation of $186,510 and $182,453 (Note 4)	136,431	129,548
Capitalized Software, net of accumulated amortization of $124,281 and $117,100	311,229	309,133
Investments Available for Sale (Note 6)	84,214	83,008
Trading Securities (Note 6)	56,461	56,325
Investment in Unconsolidated Affiliate (Note 2)	66,691	60,954
Other Assets, net	21,261	20,640
Total Assets	1,293,626	1,294,559
Current Liabilities:
Accounts payable	2,241	1,999
Accrued liabilities (Note 4)	115,408	147,044
Deferred revenue	1,228	2,030
Total Current Liabilities	118,877	151,073
Deferred Income Taxes	92,477	93,751
Other Long-term Liabilities (Note 11)	10,832	8,276
Total Liabilities	222,186	253,100
Commitments and Contingencies (Note 12)
SEI Investments shareholders' equity:
Common stock, $.01 par value, 750,000 shares authorized; 175,469 and 176,506 shares issued and outstanding	1,755	1,765
Capital in excess of par value	587,971	577,949
Retained earnings	460,727	443,702
Accumulated other comprehensive income, net	4,091	1,900
Total SEI Investments shareholders' equity	1,054,544	1,025,316
Noncontrolling interest	16,896	16,143
Total Equity	1,071,440	1,041,459
Total Liabilities and Equity	$ 1,293,626	$ 1,294,559

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Lines Of Credit (Details) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012 USD ($)	Mar. 31, 2012 Canadian Subsidiary [Member] CAD
Line of Credit Facility [Line Items]
Credit Agreement, years	P5Y
Credit facility	$ 300,000	2,000
Credit facility, expiration date	February 2017
Credit facility interest accrued, percentage above LIBOR	1.25%
Credit facility, commitment fee per annum on daily unused portion, percent	0.15%
Aggregate amount that may increase under credit facility	$ 100,000

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Consolidated Statements Of Comprehensive Income (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Consolidated Statements Of Comprehensive Income [Abstract]
Unrealized holding gains (losses) during the period, income tax expense	$ 7	$ 112
Reclassification adjustment for gains realized in net income, income tax expense	$ 35	$ 60

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Variable Interest Entities - Investment Products (Details)	3 Months Ended
	Mar. 31, 2012
Variable Interest Entities - Investment Products [Abstract]
Percentage not approached by expected return on any VIE investment	50.00%

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Investment In Unconsolidated Affiliate (Tables)

3 Months Ended

Mar. 31, 2012

Investment In Unconsolidated Affiliate [Abstract]

Condensed Statement Of Operations Of LSV

	Three Months Ended March 31,
	2012		2011
Revenues	$	77,465	$	79,402
Net income		66,673		69,946

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Composition Of Certain Financial Statement Captions (Receivables) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Composition Of Certain Financial Statement Captions [Abstract]
Trade receivables	$ 36,162	$ 37,822
Fees earned, not billed	106,670	92,916
Other receivables	5,154	12,295
Gross receivables	147,986	143,033
Less: Allowance for doubtful accounts	(876)	(924)
Receivables, net	$ 147,110	$ 142,109

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Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2012

Fair Value Measurements [Abstract]

Fair Value Of Certain Financial Assets And Liabilities

	At March 31, 2012
	Fair Value Measurements at Reporting Date Using
Assets	Total		Quoted Prices in Active  Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Equity available-for-sale securities	$	12,847	$	12,847	$	0	$	0
Fixed income available-for-sale securities		71,367		0		71,367		0
Fixed income securities owned		21,053		0		21,053		0
Trading securities		56,461		4,220		0		52,241
	$	161,728	$	17,067	$	92,420	$	52,241

	At December 31, 2011
	Fair Value Measurements at Reporting Date Using
Assets	Total		Quoted Prices in Active  Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Equity available-for-sale securities	$	8,010	$	8,010	$	0	$	0
Fixed income available-for-sale securities		74,998		0		74,998		0
Fixed income securities owned		20,949		0		20,949		0
Trading securities		56,325		3,702		0		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, 2012	$	52,623
Purchases		0
Issuances		0
Principal prepayments and settlements		(3,267	)
Sales		0
Total gains or (losses) (realized/unrealized):
Included in earnings		2,885
Included in other comprehensive income		0
Transfers in and out of Level 3		0
Balance March 31, 2012	$	52,241

	Trading Securities
Balance, January 1, 2011	$	100,645
Purchases		0
Issuances		0
Principal prepayments and settlements		(3,441	)
Sales		(34,706	)
Total gains or (losses) (realized/unrealized):
Included in earnings		6,864
Included in other comprehensive income		0
Transfers in and out of Level 3		0
Balance March 31, 2011	$	69,362

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Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash flows from operating activities:
Net income	$ 50,235	$ 58,040
Adjustments to reconcile net income to net cash provided by operating activities	(11,011)	296
Net cash provided by operating activities	39,224	58,336
Cash flows from investing activities:
Additions to property and equipment	(12,116)	(7,368)
Additions to capitalized software	(9,277)	(10,655)
Purchases of marketable securities	(9,646)	(27,307)
Prepayments and maturities of marketable securities	10,464	10,140
Sales of marketable securities	720	36,812
Sales of other investments	0	4,905
Net cash (used in) provided by investing activities	(19,855)	6,527
Cash flows from financing activities:
Payments on long-term debt	0	(35,000)
Purchase and retirement of common stock	(36,463)	(39,501)
Proceeds from issuance of common stock	12,362	10,594
Tax benefit on stock options exercised	(1,609)	791
Payment of dividends	(26,518)	0
Net cash used in financing activities	(52,228)	(63,116)
Net (decrease) increase in cash and cash equivalents	(32,859)	1,747
Cash and cash equivalents, beginning of period	420,986	496,292
Cash and cash equivalents, end of period	$ 388,127	$ 498,039

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Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Consolidated Balance Sheets [Abstract]
Receivables, allowance for doubtful accounts	$ 876	$ 924
Property and Equipment, accumulated depreciation	186,510	182,453
Capitalized Software, accumulated amortization	$ 124,281	$ 117,100
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	750,000,000	750,000,000
Common stock, shares issued	175,469,000	176,506,000
Common stock, shares outstanding	175,469,000	176,506,000

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Business Segment Information

3 Months Ended

Mar. 31, 2012

Business Segment Information [Abstract]

Business Segment Information

Note 10. 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.

The information in the following tables is derived from the Company's internal financial reporting used for corporate management purposes. There are no inter-segment revenues for the three months ended March 31, 2012 and 2011. Management evaluates Company assets on a consolidated basis during interim periods. The accounting policies of the reportable business segments are the same as those described in Note 1 to the Consolidated Financial Statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2011.

The following tables highlight certain unaudited financial information about each of the Company's business segments for the three months ended March 31, 2012 and 2011.

	Private Banks			Investment Advisors			Institutional Investors			Investment Managers			Investments In New Businesses			Total
	For the Three Months Ended March 31, 2012
Revenues	$	87,988		$	49,468		$	53,317		$	46,211		$	914		$	237,898
Expenses		87,517			29,301			28,100			30,426			3,698			179,042
Operating profit (loss)	$	471		$	20,167		$	25,217		$	15,785		$	(2,784	)	$	58,856
Operating margin		1	%		41	%		47	%		34	%		N/A			25	%

	Private Banks			Investment Advisors			Institutional Investors			Investment Managers			Investments In New Businesses			Total
	For the Three Months Ended March 31, 2011
Revenues	$	86,709		$	48,108		$	53,185		$	43,441		$	1,050		$	232,493
Expenses		82,403			27,040			26,953			27,999			3,125			167,520
Operating profit (loss)	$	4,306		$	21,068		$	26,232		$	15,442		$	(2,075	)	$	64,973
Operating margin		5	%		44	%		49	%		36	%		N/A			28	%

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

	2012			2011
Total operating profit from segments above	$	58,856		$	64,973
Corporate overhead expenses		(11,082	)		(10,648	)
Noncontrolling interest reflected in segments		315			272
Income from operations	$	48,089		$	54,597

The following tables provide additional information for the three months ended March 31, 2012 and 2011 pertaining to our business segments:

	Capital Expenditures				Depreciation
	2012		2011		2012		2011
Private Banks	$	11,842	$	11,030	$	3,728	$	4,038
Investment Advisors		4,141		3,742		494		591
Institutional Investors		1,231		881		262		292
Investment Managers		3,053		1,784		476		503
Investments in New Businesses		272		212		334		30
Total from business segments	$	20,539	$	17,649	$	5,294	$	5,454
Corporate Overhead		854		374		138		157
	$	21,393	$	18,023	$	5,432	$	5,611

	Amortization
	2012		2011
Private Banks	$	4,685	$	4,229
Investment Advisors		1,716		1,418
Institutional Investors		302		167
Investment Managers		201		115
Investments in New Businesses		277		59
Total from business segments	$	7,181	$	5,988
Corporate Overhead		441		243
	$	7,622	$	6,231

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Document And Entity Information	3 Months Ended
	Mar. 31, 2012	Apr. 30, 2012
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2012
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q1
Trading Symbol	SEIC
Entity Registrant Name	SEI INVESTMENTS CO
Entity Central Index Key	0000350894
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		175,533,170

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Income Taxes

3 Months Ended

Mar. 31, 2012

Income Taxes [Abstract]

Income Taxes

Note 11. Income Taxes

The gross liability for unrecognized tax benefits at March 31, 2012 and December 31, 2011 was $11,757 and $9,410, respectively, exclusive of interest and penalties, of which $10,043 and $8,320 would affect the effective tax rate if the Company were to recognize the tax benefit.

The Company classifies interest and penalties on unrecognized tax benefits as income tax expense. As of March 31, 2012 and December 31, 2011, the combined amount of accrued interest and penalties related to tax positions taken on tax returns was $843 and $634, respectively.

	March 31, 2012		December 31, 2011
Gross liability for unrecognized tax benefits, exclusive of interest and penalties	$	11,757	$	9,410
Interest and penalties on unrecognized benefits		843		634
Total gross uncertain tax positions	$	12,600	$	10,044
Amount included in Current liabilities	$	1,768	$	1,768
Amount included in Other long-term liabilities		10,832		8,276
	$	12,600	$	10,044

The Company's effective tax rates were 37.2 percent and 37.1 percent for the three months ended March 31, 2012 and 2011, respectively. The Company files income tax returns in the United States on a consolidated basis and in many U.S. state and foreign jurisdictions. The Company is subject to examination of income tax returns by the Internal Revenue Service (IRS) and other domestic and  foreign tax authorities. The Company is no longer subject to U.S. federal income tax examination for years before 2007 and is no longer subject to state, local or foreign income tax examinations by authorities for years before 2006.

The Company estimates it will recognize $1,768 of unrecognized tax benefits within the next twelve months due to the expiration of the statute of limitations and resolution of income tax audits. These unrecognized tax benefits are related to tax positions taken on certain federal, state, and foreign tax returns. However, the timing of the resolution of income tax examinations is highly uncertain, and the amounts ultimately paid, if any, upon resolution of the issues raised by the taxing authorities may differ materially from the amounts accrued for each year. While it is reasonably possible that some issues under examination could be resolved in the next twelve months, based upon the current facts and circumstances, the Company cannot reasonably estimate the timing of such resolution or total range of potential changes as it relates to the current unrecognized tax benefits that are recorded as part of the Company's financial statements.

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Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Revenues:
Asset management, administration and distribution fees	$ 172,954	$ 167,504
Information processing and software servicing fees	56,200	55,824
Transaction-based and trade execution fees	8,744	9,165
Total revenues	237,898	232,493
Expenses:
Subadvisory, distribution and other asset management costs	28,467	26,296
Software royalties and other information processing costs	6,477	7,017
Brokerage commissions	6,307	6,581
Compensation, benefits and other personnel	78,543	71,025
Stock-based compensation	4,033	3,732
Consulting, outsourcing and professional fees	26,955	25,998
Data processing and computer related	11,465	11,303
Facilities, supplies and other costs	14,508	14,102
Amortization	7,622	6,231
Depreciation	5,432	5,611
Total expenses	189,809	177,896
Income from operations	48,089	54,597
Net gain from investments	3,205	7,278
Interest and dividend income	1,487	1,544
Interest expense	(161)	(204)
Equity in earnings of unconsolidated affiliate	27,330	28,949
Net income before income taxes	79,950	92,164
Income taxes	29,715	34,124
Net income	50,235	58,040
Less: Net income attributable to the noncontrolling interest	(270)	(312)
Net income attributable to SEI Investments Company	$ 49,965	$ 57,728
Basic earnings per common share	$ 0.28	$ 0.31
Diluted earnings per common share	$ 0.28	$ 0.31

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Fair Value Measurements

3 Months Ended

Mar. 31, 2012

Fair Value Measurements [Abstract]

Fair Value Measurements

Note 5. 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 and Level 2 financial assets consist mainly of investments in equity and fixed-income mutual funds that are quoted daily and Government National Mortgage Association (GNMA) and other U.S. government agency securities that are single issuer pools that are valued based on current market data for the specific issue owned or pools of similar securities. Level 3 financial assets primarily consist of senior note obligations issued by SIVs. The Company did not have any Level 3 financial liabilities at March 31, 2012 or December 31, 2011. There were no transfers of financial assets between levels within the fair value hierarchy during the three months ended March 31, 2012.

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 a third party independent firm to assist in determining the fair value of the SIV security owned. Given the lack of any reliable market data on the SIV security, the firm utilized a valuation model that employs a net asset approach which considers the value of the underlying collateral of the SIV security to determine its fair value. Management evaluated the value received from the firm and considered other information, such as the existence of any current market activity, to determine the fair value of the SIV securities. As a result of this evaluation, the Company utilized the fair value of the SIV security without adjustment as provided by the third party 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 may also consider, when available, price quotes from brokers and dealers. If a price quote is available, management will compare this number to the fair value derived from the valuation model of the independent firm giving consideration to other market factors and risk premiums. Given the lack of any significant trading activity for the SIV security owned by the Company, management believes that market prices may not represent the implied fair value of the SIV security owned by the Company.

In the event a market transaction does exist for a SIV security, management evaluates the publicly available information surrounding the transaction in order to assess if the price used represents the fair value for the SIV security. In management's opinion, the current market for SIV securities does not represent any orderly and efficient market.

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

	At March 31, 2012
	Fair Value Measurements at Reporting Date Using
Assets	Total		Quoted Prices in Active  Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Equity available-for-sale securities	$	12,847	$	12,847	$	0	$	0
Fixed income available-for-sale securities		71,367		0		71,367		0
Fixed income securities owned		21,053		0		21,053		0
Trading securities		56,461		4,220		0		52,241
	$	161,728	$	17,067	$	92,420	$	52,241

	At December 31, 2011
	Fair Value Measurements at Reporting Date Using
Assets	Total		Quoted Prices in Active  Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Equity available-for-sale securities	$	8,010	$	8,010	$	0	$	0
Fixed income available-for-sale securities		74,998		0		74,998		0
Fixed income securities owned		20,949		0		20,949		0
Trading securities		56,325		3,702		0		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, 2012 to March 31, 2012:

	Trading Securities
Balance, January 1, 2012	$	52,623
Purchases		0
Issuances		0
Principal prepayments and settlements		(3,267	)
Sales		0
Total gains or (losses) (realized/unrealized):
Included in earnings		2,885
Included in other comprehensive income		0
Transfers in and out of Level 3		0
Balance March 31, 2012	$	52,241

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 March 31, 2011:

	Trading Securities
Balance, January 1, 2011	$	100,645
Purchases		0
Issuances		0
Principal prepayments and settlements		(3,441	)
Sales		(34,706	)
Total gains or (losses) (realized/unrealized):
Included in earnings		6,864
Included in other comprehensive income		0
Transfers in and out of Level 3		0
Balance March 31, 2011	$	69,362

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Composition Of Certain Financial Statement Captions

3 Months Ended

Mar. 31, 2012

Composition Of Certain Financial Statement Captions [Abstract]

Composition Of Certain Financial Statement Captions

Note 4. Composition of Certain Financial Statement Captions

Receivables

Receivables on the accompanying Consolidated Balance Sheets consist of:

	March 31, 2012			December 31, 2011
Trade receivables	$	36,162		$	37,822
Fees earned, not billed		106,670			92,916
Other receivables		5,154			12,295
		147,986			143,033
Less: Allowance for doubtful accounts		(876	)		(924	)
	$	147,110		$	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.

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.

Property and Equipment

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

	March 31, 2012			December 31, 2011
Buildings	$	137,327		$	136,949
Equipment		63,350			64,256
Land		9,929			9,929
Purchased software		89,262			77,971
Furniture and fixtures		18,222			17,999
Leasehold improvements		4,743			4,558
Construction in progress		108			339
		322,941			312,001
Less: Accumulated depreciation		(186,510	)		(182,453	)
Property and Equipment, net	$	136,431		$	129,548

The Company recognized $5,432 and $5,611 in depreciation expense related to property and equipment for the three months ended March 31, 2012 and 2011, respectively.

Accrued Liabilities

Accrued liabilities on the accompanying Consolidated Balance Sheets consist of:

	March 31, 2012		December 31, 2011
Accrued employee compensation	$	21,335	$	48,112
Accrued employee benefits and other personnel		5,816		5,408
Accrued consulting, outsourcing and professional fees		19,493		17,477
Accrued brokerage fees		8,415		8,665
Accrued sub-advisory, distribution and other asset management fees		16,500		17,091
Accrued income taxes		18,074		0
Accrued dividend payable		0		26,518
Other accrued liabilities		25,775		23,773
Total accrued liabilities	$	115,408	$	147,044

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Composition Of Certain Financial Statement Captions (Tables)

3 Months Ended

Mar. 31, 2012

Composition Of Certain Financial Statement Captions [Abstract]

Receivables

	March 31, 2012			December 31, 2011
Trade receivables	$	36,162		$	37,822
Fees earned, not billed		106,670			92,916
Other receivables		5,154			12,295
		147,986			143,033
Less: Allowance for doubtful accounts		(876	)		(924	)
	$	147,110		$	142,109

Property And Equipment

	March 31, 2012			December 31, 2011
Buildings	$	137,327		$	136,949
Equipment		63,350			64,256
Land		9,929			9,929
Purchased software		89,262			77,971
Furniture and fixtures		18,222			17,999
Leasehold improvements		4,743			4,558
Construction in progress		108			339
		322,941			312,001
Less: Accumulated depreciation		(186,510	)		(182,453	)
Property and Equipment, net	$	136,431		$	129,548

Accrued Liabilities

	March 31, 2012		December 31, 2011
Accrued employee compensation	$	21,335	$	48,112
Accrued employee benefits and other personnel		5,816		5,408
Accrued consulting, outsourcing and professional fees		19,493		17,477
Accrued brokerage fees		8,415		8,665
Accrued sub-advisory, distribution and other asset management fees		16,500		17,091
Accrued income taxes		18,074		0
Accrued dividend payable		0		26,518
Other accrued liabilities		25,775		23,773
Total accrued liabilities	$	115,408	$	147,044

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Commitments And Contingencies

3 Months Ended

Mar. 31, 2012

Commitments And Contingencies [Abstract]

Commitments And Contingencies

Note 12. Commitments and Contingencies

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. To date, the Complaints have been filed in the United States District Court for the Southern District of New York and in the United States District Court for the District of Maryland. The three complaints filed in the District of Maryland have been voluntarily dismissed by the plaintiffs. Two of them were subsequently re-filed in the Southern District of New York. Two of the complaints filed in the Southern District of New York have also been voluntarily dismissed by plaintiffs. 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. The Complaints allege that SIDCO is liable for these purportedly material misstatements and omissions under Section 11 of the Securities Act of 1933. The Complaints seek unspecified compensatory and other damages, reasonable costs and other relief. Defendants have moved to consolidate the complaints, which motion has been granted. The Court appointed lead plaintiff on July 13, 2010, and an amended consolidated class action complaint was filed on September 25, 2010 asserting substantially the same claims. Defendants moved to dismiss on November 15, 2010. On December 16, 2010, lead plaintiff informed the Court and Defendants that lead plaintiff elected to file a second amended consolidated complaint, which was filed on January 31, 2011. Defendants filed a motion to dismiss the second complaint on March 17, 2011. Oral argument on this motion was held on February 2, 2012. 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. 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 putative 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 have been removed to federal court, and plaintiffs' motions to remand are pending. These two cases have been 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 and SPTC in the two remanded actions were preempted by federal law and the Court dismissed these cases with prejudice. The Court of Appeals for the Fifth Circuit granted an expedited appeal of the United States District Court's order and judgment. The appeal was briefed, and oral argument was held on February 7, 2012. 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 April 2, 2012, SEI filed with the United States Court of Appeals for the Fifth Circuit a petition for rehearing en banc of the panel's opinion. On April 19, 2012, the Fifth Circuit Court of Appeals denied the petition for rehearing.

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. SEI and SPTC filed exceptions in the putative 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 putative 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. Following the decision by the United States District Court for the Northern District of Texas, the Court in the East Baton Rouge action issued an order staying the proceedings in the East Baton Rouge class action pending the outcome of the appeal of the order and judgment of the United States District Court for the Northern District of Texas. Following the panel opinion of the Court of Appeals on March 19, 2012, the Court in the East Baton Rouge action scheduled a hearing on class certification for September 20, 2012. 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.

Because of the uncertainty of the make-up of the classes, the specific theories of liability that may survive a motion to dismiss, 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.

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Shareholders' Equity

3 Months Ended

Mar. 31, 2012

Shareholders' Equity [Abstract]

Shareholders' Equity

Note 8. 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. All outstanding stock options have performance-based vesting provisions specific to each option grant that tie the vesting of the applicable stock options to the Company's financial performance. The Company's stock options vest at a rate of 50 percent when specified diluted earnings per share targets are achieved, and the remaining 50 percent when secondary, higher specified diluted earnings per share targets are achieved. The amount of stock-based compensation expense is based upon management's estimate of when the earnings per share targets may be achieved.

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. No options are available for grant from this plan. Grants made from the 1998 Plan continue in effect under the terms of the grant.

The Company recognized stock-based compensation expense in its Consolidated Financial Statements in the three months ended March 31, 2012 and 2011, respectively, as follows:

	Three Months Ended March 31,
	2012			2011
Stock-based compensation expense	$	4,033		$	3,732
Less: Deferred tax benefit		(1,521	)		(1,398	)
Stock-based compensation expense, net of tax	$	2,512		$	2,334

As of March 31, 2012, there was approximately $45,594 of unrecognized compensation cost remaining, adjusted for estimated forfeitures, related to unvested employee stock options that management expects will vest and is being amortized. The Company estimates that compensation cost will be recognized according to the following schedule:

Period	Stock-Based Compensation Expense
Remainder of 2012	$	11,837
2013		12,715
2014		12,521
2015		3,850
2016		2,358
2017		2,313
	$	45,594

The Company issues new common shares associated with the exercise of stock options. The total intrinsic value of options exercised during the three months ended March 31, 2012 was $3,752. The total options exercisable as of March 31, 2012 had an intrinsic value of $36,218. The total intrinsic value for options exercisable is calculated as the difference between the market value of the Company's common stock as of March 31, 2012 and the exercise price of the shares. The market value of the Company's common stock as of March 31, 2012 was $20.69 as reported by the Nasdaq Stock Market, LLC. The weighted average exercise price of the options exercisable as of March 31, 2012 was $17.36. Total options that were outstanding and exercisable as of March 31, 2012 were 26,082,000 and 10,873,000, respectively.

Common Stock Buyback

The Company's Board of Directors, under multiple authorizations, has authorized the repurchase of the Company's common stock on the open market or through private transactions. The Company purchased 1,848,000 shares at a total cost of $37,714 during the three months ended March 31, 2012. As of March 31, 2012, the Company has $58,562 of authorization remaining for the purchase of common stock under the program.

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.

Noncontrolling Interest

The following table provides a reconciliation of Noncontrolling interest on the Consolidated Balance Sheet for the period from January 1, 2012 to March 31, 2012:

	Noncontrolling interest
Balance, January 1, 2012	$	16,143
Net income attributable to noncontrolling interest		270
Foreign currency translation adjustments		483
Balance, March 31, 2012	$	16,896

The following table provides a reconciliation of Noncontrolling interest on the Consolidated Balance Sheet for the period from January 1, 2011 to March 31, 2011:

	Noncontrolling interest
Balance, January 1, 2011	$	15,155
Net income attributable to noncontrolling interest		312
Foreign currency translation adjustments		420
Balance, March 31, 2011	$	15,887

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Marketable Securities

3 Months Ended

Mar. 31, 2012

Marketable Securities [Abstract]

Marketable Securities

Note 6. Marketable Securities

Investments Available for Sale

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

	As of March 31, 2012
	Cost Amount		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
SEI-sponsored mutual funds	$	12,744	$	84	$	(13	)	$	12,815
Other mutual funds		28		4		0			32
Debt securities		67,407		3,960		0			71,367
	$	80,179	$	4,048	$	(13	)	$	84,214

	As of December 31, 2011
	Cost Amount		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
SEI-sponsored mutual funds	$	8,243	$	48	$	(360	)	$	7,931
Other mutual funds		69		10		0			79
Debt securities		70,604		4,394		0			74,998
	$	78,916	$	4,452	$	(360	)	$	83,008

Net unrealized holding gains at March 31, 2012 and December 31, 2011 were $2,545 (net of income tax expense of $1,490) 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.

Gross realized gains and losses from available-for-sale securities during the three months ended March 31, 2012 and 2011 were minimal. 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 classified as available-for-sale securities are issued by GNMA and are backed by the full faith and credit of the U.S. government. These securities were purchased to satisfy applicable regulatory requirements of SEI Private Trust Company (SPTC) and have maturity dates which range from 2020 to 2041.

Trading Securities

Trading securities of the Company consist of:

	As of March 31, 2012
	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Fair Value
SIV securities	$	143,096	$	0	$	(92,073	)	$	51,023
LSV-sponsored mutual funds		2,049		2,171		0			4,220
Other investments		1,215		3		0			1,218
	$	146,360	$	2,174	$	(92,073	)	$	56,461

	As of December 31, 2011
	Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Fair Value
SIV securities	$	146,363	$	0	$	(94,955	)	$	51,408
LSV-sponsored mutual funds		2,049		1,653		0			3,702
Other investments		1,215		0		0			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 the three months ended March 31, 2012 and 2011, the Company recognized gains from SIV securities of $2,882 and $6,864, respectively. Of the gains recognized during the three months ended March 31, 2012, $2,111 resulted from cash payments received from the SIV securities and $771 was from an increase in fair value at March 31, 2012. Of the gains recognized during the three months ended March 31, 2011, $2,049 resulted from cash payments received from the SIV securities and $4,815 was from an increase in fair value at March 31, 2011. The net gains from the SIV securities are reflected in Net gain from investments on the accompanying Consolidated Statements of Operations.

In January 2011, the Company sold the senior note obligation originally issued by Stanfield Victoria. There was no gain or loss recognized by the Company from the sale of the note in 2011 as the fair value of the Stanfield Victoria note at December 31, 2010 was not different than the sale price received.

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 and Australian companies as well as various other global securities. The underlying securities held by the funds are translated into U.S. dollars within the funds. The net gains (losses) from the change in fair value of the funds during the three months ended March 31, 2012 and 2011 were minimal.

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 $21,053 and $20,949 at March 31, 2012 and December 31, 2011, respectively. The net gains (losses) from the change in fair value of the securities during the three months ended March 31, 2012 and 2011 were minimal.

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Lines Of Credit

3 Months Ended

Mar. 31, 2012

Lines Of Credit [Abstract]

Lines Of Credit

Note 7. 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 replaced the five-year Credit Agreement with JP Morgan Chase Bank, N.A. The Credit Facility 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 LIBOR. There is also a commitment fee equal to 0.15 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 agreement may be terminated. The Company had no borrowings through the Credit Facility at March 31, 2012. The Company was in compliance with all covenants of the Credit Facility at March 31, 2012.

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 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 the three months ended March 31, 2012.

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Accumulated Comprehensive Income (Loss)

3 Months Ended

Mar. 31, 2012

Accumulated Comprehensive Income (Loss) [Abstract]

Accumulated Comprehensive Income (Loss)

Note 9. Accumulated Comprehensive Income (Loss)

Accumulated other comprehensive income (loss), net of tax, consists of:

	Foreign Currency Translation Adjustments			Unrealized Holding Gains (Losses) on Investments			Accumulated Other Comprehensive Income (Loss)
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			0			1,369
Total accumulated comprehensive income attributable to SEI Investments Company at December 31, 2011	$	(674	)	$	2,574		$	1,900
Total comprehensive income for the three months ended March 31, 2012	$	2,703		$	(29	)	$	2,674
Less: Total comprehensive income attributable to noncontrolling interest for the three months ended March 31, 2012		(483	)		0			(483	)
Total comprehensive income attributable to SEI Investments Company for the three months ended March 31, 2012	$	2,220		$	(29	)	$	2,191
Total accumulated comprehensive income at March 31, 2012	$	660		$	2,545		$	3,205
Less: Total accumulated comprehensive loss attributable to noncontrolling interest at March 31, 2012		886			0			886
Total accumulated comprehensive income attributable to SEI Investments Company at March 31, 2012	$	1,546		$	2,545		$	4,091

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Investment In Unconsolidated Affiliate (Condensed Statement Of Operations Of LSV) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Investments in and Advances to Affiliates [Line Items]
Revenues	$ 237,898	$ 232,493
Net income	49,965	57,728
LSV [Member]
Investments in and Advances to Affiliates [Line Items]
Revenues	77,465	79,402
Net income	$ 66,673	$ 69,946

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Business Segment Information (Schedule Of Financial Information About Business Segments) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Segment Reporting Information [Line Items]
Revenues	$ 237,898	$ 232,493
Expenses	179,042	167,520
Operating profit (loss)	58,856	64,973
Operating margin	25.00%	28.00%
Private Banks [Member]
Segment Reporting Information [Line Items]
Revenues	87,988	86,709
Expenses	87,517	82,403
Operating profit (loss)	471	4,306
Operating margin	1.00%	5.00%
Investment Advisors [Member]
Segment Reporting Information [Line Items]
Revenues	49,468	48,108
Expenses	29,301	27,040
Operating profit (loss)	20,167	21,068
Operating margin	41.00%	44.00%
Institutional Investors [Member]
Segment Reporting Information [Line Items]
Revenues	53,317	53,185
Expenses	28,100	26,953
Operating profit (loss)	25,217	26,232
Operating margin	47.00%	49.00%
Investment Managers [Member]
Segment Reporting Information [Line Items]
Revenues	46,211	43,441
Expenses	30,426	27,999
Operating profit (loss)	15,785	15,442
Operating margin	34.00%	36.00%
Investments In New Businesses [Member]
Segment Reporting Information [Line Items]
Revenues	914	1,050
Expenses	3,698	3,125
Operating profit (loss)	$ (2,784)	$ (2,075)

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Summary Of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2012

Summary Of Significant Accounting Policies [Abstract]

Calculation Of Basic And Diluted Earnings Per Share

For the Three Month Period Ended March 31, 2012
	Income (Numerator)		Shares (Denominator)		Per Share Amount
Basic earnings per common share	$	49,965		176,348	$	.28
Dilutive effect of stock options		0		1,320
Diluted earnings per common share	$	49,965		177,668	$	.28

		000,000		000,000		000,000
	For the Three Month Period Ended March 31, 2011
	Income (Numerator)		Shares (Denominator)		Per Share Amount
Basic earnings per common share	$	57,728		185,787	$	.31
Dilutive effect of stock options		0		2,708
Diluted earnings per common share	$	57,728		188,495	$	.31

Adjustments To Reconcile Net Income To Net Cash Provided By Operating Activities

	2012			2011
Net income	$	50,235		$	58,040
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation		5,432			5,611
Amortization		7,622			6,231
Equity in earnings of unconsolidated affiliate		(27,330	)		(28,949	)
Distributions received from unconsolidated affiliate		21,593			23,802
Stock-based compensation		4,033			3,732
Provision for losses on receivables		(48	)		(236	)
Deferred income tax expense		(517	)		2,345
Net realized gains from investments		(3,205	)		(7,278	)
Change in other long-term liabilities		2,556			294
Change in other assets		(1,385	)		(1,841	)
Other		2,656			3,036
Change in current asset and liabilities
Decrease (increase) in
Receivables from regulated investment companies		(9,183	)		824
Receivables		(4,413	)		(3,551	)
Other current assets		(1,687	)		(1,210	)
Increase (decrease) in
Accounts payable		242			(1,841	)
Accrued liabilities		(6,575	)		(151	)
Deferred revenue		(802	)		(522	)
Total adjustments		(11,011	)		296
Net cash provided by operating activities	$	39,224		$	58,336

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Shareholders' Equity (Tables)

3 Months Ended

Mar. 31, 2012

Shareholders' Equity [Abstract]

Stock-Based Compensation Expense

	Three Months Ended March 31,
	2012			2011
Stock-based compensation expense	$	4,033		$	3,732
Less: Deferred tax benefit		(1,521	)		(1,398	)
Stock-based compensation expense, net of tax	$	2,512		$	2,334

Schedule Of Recognition Of Compensation Cost

Period	Stock-Based Compensation Expense
Remainder of 2012	$	11,837
2013		12,715
2014		12,521
2015		3,850
2016		2,358
2017		2,313
	$	45,594

Schedule Of Reconciliation Of Noncontrolling Interest On The Consolidated Balance Sheet

	Noncontrolling interest
Balance, January 1, 2012	$	16,143
Net income attributable to noncontrolling interest		270
Foreign currency translation adjustments		483
Balance, March 31, 2012	$	16,896

	Noncontrolling interest
Balance, January 1, 2011	$	15,155
Net income attributable to noncontrolling interest		312
Foreign currency translation adjustments		420
Balance, March 31, 2011	$	15,887

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Shareholders' Equity (Schedule Of Reconciliation Of Noncontrolling Interest On The Consolidated Balance Sheet) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Shareholders' Equity [Abstract]
Beginning balance	$ 16,143	$ 15,155
Net income attributable to noncontrolling interest	270	312
Foreign currency translation adjustments	483	420
Ending balance	$ 16,896	$ 15,887

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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	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Fair Value Measurements [Abstract]
Beginning balance, January 1	$ 52,623	$ 100,645
Purchases	0	0
Issuances	0	0
Principal prepayments and settlements	(3,267)	(3,441)
Sales	0	(34,706)
Total gains or (losses) (realized/unrealized), Included in earnings	2,885	6,864
Total gains or (losses) (realized/unrealized), Included in other comprehensive income	0	0
Transfers in and out of Level 3	0	0
Ending balance, March 31	$ 52,241	$ 69,362

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Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 50,235	$ 58,040
Other comprehensive income, net of tax:
Foreign currency translation adjustments	2,703	2,828
Unrealized holding loss on investments:
Unrealized holding gains (losses) during the period, net of income tax expense of $7 and $112	31	(170)
Less: reclassification adjustment for gains realized in net income, net of income tax expense of $35 and $60	(60)	(103)
Unrealized holding loss on investments	(29)	(273)
Total other comprehensive income, net of tax	2,674	2,555
Comprehensive income	52,909	60,595
Comprehensive income attributable to the noncontrolling interest	(753)	(732)
Comprehensive income attributable to SEI Investments Company	$ 52,156	$ 59,863

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Variable Interest Entities - Investment Products

3 Months Ended

Mar. 31, 2012

Variable Interest Entities - Investment Products [Abstract]

Variable Interest Entities - Investment Products

Note 3. 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 and net capital gains 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. Some of the Company's investment products have been determined to be VIEs at inception.

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 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, is not 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 not significant. 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 not significant to the total assets of the Company.

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Accumulated Comprehensive Income (Loss) (Tables)

3 Months Ended

Mar. 31, 2012

Accumulated Comprehensive Income (Loss) [Abstract]

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

	Foreign Currency Translation Adjustments			Unrealized Holding Gains (Losses) on Investments			Accumulated Other Comprehensive Income (Loss)
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			0			1,369
Total accumulated comprehensive income attributable to SEI Investments Company at December 31, 2011	$	(674	)	$	2,574		$	1,900
Total comprehensive income for the three months ended March 31, 2012	$	2,703		$	(29	)	$	2,674
Less: Total comprehensive income attributable to noncontrolling interest for the three months ended March 31, 2012		(483	)		0			(483	)
Total comprehensive income attributable to SEI Investments Company for the three months ended March 31, 2012	$	2,220		$	(29	)	$	2,191
Total accumulated comprehensive income at March 31, 2012	$	660		$	2,545		$	3,205
Less: Total accumulated comprehensive loss attributable to noncontrolling interest at March 31, 2012		886			0			886
Total accumulated comprehensive income attributable to SEI Investments Company at March 31, 2012	$	1,546		$	2,545		$	4,091

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Composition Of Certain Financial Statement Captions (Accrued Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Composition Of Certain Financial Statement Captions [Abstract]
Accrued employee compensation	$ 21,335	$ 48,112
Accrued employee benefits and other personnel	5,816	5,408
Accrued consulting, outsourcing and professional fees	19,493	17,477
Accrued brokerage fees	8,415	8,665
Accrued sub-advisory, distribution and other asset management fees	16,500	17,091
Accrued income taxes	18,074	0
Accrued dividend payable	0	26,518
Other accrued liabilities	25,775	23,773
Total accrued liabilities	$ 115,408	$ 147,044

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Summary Of Significant Accounting Policies (Policy)

3 Months Ended

Mar. 31, 2012

Summary Of Significant Accounting Policies [Abstract]

Nature Of Operations

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.

Basis Of Presentation

Basis of Presentation

The accompanying Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States of America. Certain financial information and accompanying note disclosure normally included in the Company's Annual Report on Form 10-K has been condensed or omitted. The interim financial information is unaudited but reflects all adjustments (consisting of only normal recurring adjustments) which are, in the opinion of management, necessary for a fair statement of financial position of the Company as of March 31, 2012, the results of operations for the three months ended March 31, 2012 and 2011, and cash flows for the three month periods ended March 31, 2012 and 2011. These interim Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and the Notes to the Consolidated Financial Statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2011.

There have been no significant changes in significant accounting policies during the three months ended March 31, 2012 as compared to the significant accounting policies described in the Company's Annual Report on Form 10-K for the year ended December 31, 2011.

Cash And Cash Equivalents

Cash and Cash Equivalents

Cash and cash equivalents includes $224,019 and $281,760 at March 31, 2012 and December 31, 2011, respectively, primarily invested in SEI-sponsored open-ended money market mutual funds.

Restricted Cash

Restricted Cash

Restricted cash includes $5,000 at March 31, 2012 and December 31, 2011 segregated for regulatory purposes related to trade-execution services conducted by SEI Investments (Europe) Limited. Restricted cash also includes $1,000 at March 31, 2012 and December 31, 2011 segregated in special reserve accounts for the benefit of customers of the Company's broker-dealer subsidiary, SEI Investments Distribution Co. (SIDCO), in accordance with certain rules established by the Securities and Exchange Commission for broker-dealers.

Capitalized Software

Capitalized

Software

The Company capitalized $9,277 and $10,655 of software development costs during the three months ended March 31, 2012 and 2011, respectively. As of March 31, 2012, capitalized software placed into service included on the accompanying Consolidated Balance Sheet had a weighted average remaining life of approximately 10.3 years. Amortization expense related to capitalized software was $7,181 and $5,981 during the three months ended March 31, 2012 and 2011, respectively.

Software development costs capitalized during the three months ended March 31, 2012 and 2011 relates to the continued development of the Global Wealth Platform (GWP). As of March 31, 2012, the net book value of GWP was $289,623, net of accumulated amortization of $94,826. Capitalized software development costs in-progress at March 31, 2012 associated with future releases to GWP were $20,830. GWP has an estimated useful life of 15 years and a weighted average remaining life of 10.3 years. Amortization expense for GWP was $7,064 and $5,840 during the three months ended March 31, 2012 and 2011, respectively.

Earnings Per Share

Earnings per Share

The calculations of basic and diluted earnings per share for the three months ended March 31, 2012 and 2011 are:

		000,000		000,000		000,000
	For the Three Month Period Ended March 31, 2012
	Income (Numerator)		Shares (Denominator)		Per Share Amount
Basic earnings per common share	$	49,965		176,348	$	.28
Dilutive effect of stock options		0		1,320
Diluted earnings per common share	$	49,965		177,668	$	.28

		000,000		000,000		000,000
	For the Three Month Period Ended March 31, 2011
	Income (Numerator)		Shares (Denominator)		Per Share Amount
Basic earnings per common share	$	57,728		185,787	$	.31
Dilutive effect of stock options		0		2,708
Diluted earnings per common share	$	57,728		188,495	$	.31

Employee stock options to purchase 14,329,000 and 7,609,000 shares of common stock, with an average exercise price of $23.43 and $28.26, were outstanding during the three month periods ended March 31, 2012 and 2011, respectively, but not included in the computation of diluted earnings per common share because the effect on diluted earnings per common share would have been anti-dilutive.

Statements Of Cash Flows

For purposes of the Consolidated Statements of Cash Flows, the Company considers investment instruments purchased with an original maturity of three months or less to be cash equivalents.

The following table provides the details of the adjustments to reconcile net income to net cash provided by operating activities for the three months ended March 31:

	2012			2011
Net income	$	50,235		$	58,040
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation		5,432			5,611
Amortization		7,622			6,231
Equity in earnings of unconsolidated affiliate		(27,330	)		(28,949	)
Distributions received from unconsolidated affiliate		21,593			23,802
Stock-based compensation		4,033			3,732
Provision for losses on receivables		(48	)		(236	)
Deferred income tax expense		(517	)		2,345
Net realized gains from investments		(3,205	)		(7,278	)
Change in other long-term liabilities		2,556			294
Change in other assets		(1,385	)		(1,841	)
Other		2,656			3,036
Change in current asset and liabilities
Decrease (increase) in
Receivables from regulated investment companies		(9,183	)		824
Receivables		(4,413	)		(3,551	)
Other current assets		(1,687	)		(1,210	)
Increase (decrease) in
Accounts payable		242			(1,841	)
Accrued liabilities		(6,575	)		(151	)
Deferred revenue		(802	)		(522	)
Total adjustments		(11,011	)		296
Net cash provided by operating activities	$	39,224		$	58,336