SEI Investments (SEIC) 10-Q 25 Oct 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Oct. 21, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	0-10200
Entity Registrant Name	SEI INVESTMENTS COMPANY
Entity Incorporation, State or Country Code	PA
Entity Tax Identification Number	23-1707341
Entity Address, Address Line One	1 Freedom Valley Drive
Entity Address, City or Town	Oaks
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19456
City Area Code	610
Local Phone Number	676-1000
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	SEIC
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		139,452,507
Entity Central Index Key	0000350894
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Amendment Flag	false
Current Fiscal Year End Date	--12-31

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current Assets:
Cash and cash equivalents	$ 793,883	$ 784,626
Restricted cash	351	3,101
Receivables from investment products	59,808	55,271
Receivables, net of allowance for doubtful accounts of $2,669 and $1,100	442,187	385,219
Securities owned	31,770	34,064
Other current assets	42,615	38,696
Total Current Assets	1,370,614	1,300,977
Property and Equipment, net of accumulated depreciation of $400,679 and $378,639	183,802	189,052
Operating Lease Right-of-Use Assets	35,145	38,397
Capitalized Software, net of accumulated amortization of $531,923 and $491,739	250,280	270,977
Available for Sale and Equity Securities	140,079	105,419
Investments in Affiliated Funds, at fair value	6,893	6,166
Investment in Unconsolidated Affiliate	39,872	98,433
Goodwill	64,489	64,489
Intangible Assets, net of accumulated amortization of $15,768 and $12,456	31,992	24,304
Deferred Contract Costs	34,263	33,781
Deferred Income Taxes	2,148	2,972
Other Assets, net	32,224	32,289
Total Assets	2,191,801	2,167,256
Current Liabilities:
Accounts payable	10,772	7,766
Accrued liabilities	231,043	299,845
Current portion of long-term operating lease liabilities	10,412	8,579
Deferred revenue	1,235	1,085
Total Current Liabilities	253,462	317,275
Long-term Income Taxes Payable	803	803
Deferred Income Taxes	47,434	55,159
Long-term Operating Lease Liabilities	29,857	34,058
Other Long-term Liabilities	22,157	20,054
Total Liabilities	353,713	427,349
Commitments and Contingencies
Shareholders' Equity:
Common stock, $0.01 par value, 750,000 shares authorized; 139,305 and 143,396 shares issued and outstanding	1,393	1,434
Capital in excess of par value	1,228,085	1,190,001
Retained earnings	629,153	565,270
Accumulated other comprehensive loss, net	(20,543)	(16,798)
Total Shareholders' Equity	1,838,088	1,739,907
Total Liabilities and Shareholders' Equity	$ 2,191,801	$ 2,167,256

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Receivables, allowance for doubtful accounts	$ 2,669	$ 1,100
Property and equipment, accumulated depreciation	400,679	378,639
Capitalized Software, accumulated amortization	531,923	491,739
Intangible Assets, accumulated amortization	$ 15,768	$ 12,456
Shareholders' Equity:
Common stock, par value (in USD per share)	$ 0.01	$ 0.01
Common stock, shares authorized	750,000,000	750,000,000
Common stock, shares issued	139,305,000	143,396,000
Common stock, shares outstanding	139,305,000	143,396,000

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenues:
Revenues	$ 485,322	$ 424,927	$ 1,416,659	$ 1,240,335
Expenses:
Subadvisory, distribution and other asset management costs	55,619	45,126	161,610	134,645
Software royalties and other information processing costs	7,348	6,992	20,561	21,828
Compensation, benefits and other personnel	150,188	134,795	429,188	391,607
Stock-based compensation	11,318	6,467	31,173	20,458
Consulting, outsourcing and professional fees	55,868	57,949	165,657	168,350
Data processing and computer related	26,650	24,437	79,746	71,647
Facilities, supplies and other costs	14,124	16,679	49,851	47,448
Amortization	14,674	13,200	43,749	39,417
Depreciation	8,408	7,945	25,141	23,058
Total expenses	344,197	313,590	1,006,676	918,458
Income from operations	141,125	111,337	409,983	321,877
Net (loss) gain from investments	(575)	776	134	(1,310)
Interest and dividend income	892	1,009	2,715	5,582
Interest expense	(101)	(153)	(354)	(456)
Equity in earnings of unconsolidated affiliate	35,005	28,305	103,420	86,488
Income before income taxes	176,346	141,274	515,898	412,181
Income taxes	38,301	30,178	114,605	90,777
Net income	$ 138,045	$ 111,096	$ 401,293	$ 321,404
Basic earnings per common share (in USD per share)	$ 0.98	$ 0.76	$ 2.83	$ 2.18
Shares used to compute basic earnings per share (in shares)	140,507	145,812	141,928	147,586
Diluted earnings per common share (in USD per share)	$ 0.97	$ 0.75	$ 2.79	$ 2.14
Shares used to compute diluted earnings per share (in shares)	142,426	147,907	143,981	149,958
Dividends declared per common share (in USD per share)	$ 0	$ 0	$ 0.37	$ 0.35
Asset management, administration and distribution fees
Revenues:
Revenues	$ 393,296	$ 339,609	$ 1,143,451	$ 992,039
Information processing and software servicing fees
Revenues:
Revenues	$ 92,026	$ 85,318	$ 273,208	$ 248,296

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 138,045	$ 111,096	$ 401,293	$ 321,404
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(5,546)	7,085	(2,867)	(5,051)
Unrealized (loss) gain on investments:
Unrealized (losses) gains during the period, net of income taxes of $208, $154, $453 and $(218)	(713)	(542)	(1,548)	702
Reclassification adjustment for losses realized in net income, net of income taxes of $(67), $(63), $(190) and $(126)	238	238	670	455
Total other comprehensive (loss) income, net of tax	(6,021)	6,781	(3,745)	(3,894)
Comprehensive income	$ 132,024	$ 117,877	$ 397,548	$ 317,510

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Unrealized gains during the period, taxes	$ 208	$ 154	$ 453	$ (218)
Reclassification adjustment for losses realized in net income, taxes	$ (67)	$ (63)	$ (190)	$ (126)

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Capital In Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance, shares at Dec. 31, 2019		149,745
Beginning balance at Dec. 31, 2019	$ 1,738,778	$ 1,497	$ 1,158,900	$ 601,885	$ (23,504)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	321,404			321,404
Other comprehensive income (loss)	(3,894)				(3,894)
Purchase and retirement of common stock, shares		(6,185)
Purchase and retirement of common stock	(325,644)	$ (62)	(34,999)	(290,583)
Issuance of common stock under employee stock purchase plan, shares		73
Issuance of common stock under employee stock purchase plan	3,401	$ 1	3,400
Issuance of common stock upon exercise of stock options, shares		858
Issuance of common stock upon exercise of stock options	26,392	$ 9	26,383
Stock-based compensation	20,458		20,458
Dividends declared	(51,462)			(51,462)
Ending balance, shares at Sep. 30, 2020		144,491
Ending balance at Sep. 30, 2020	1,729,433	$ 1,445	1,174,142	581,244	(27,398)
Beginning balance, shares at Jun. 30, 2020		146,445
Beginning balance at Jun. 30, 2020	1,708,625	$ 1,464	1,174,411	566,929	(34,179)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	111,096			111,096
Other comprehensive income (loss)	6,781				6,781
Purchase and retirement of common stock, shares		(2,110)
Purchase and retirement of common stock	(108,742)	$ (22)	(11,939)	(96,781)
Issuance of common stock under employee stock purchase plan, shares		26
Issuance of common stock under employee stock purchase plan	1,153	$ 1	1,152
Issuance of common stock upon exercise of stock options, shares		130
Issuance of common stock upon exercise of stock options	4,053	$ 2	4,051
Stock-based compensation	6,467		6,467
Ending balance, shares at Sep. 30, 2020		144,491
Ending balance at Sep. 30, 2020	$ 1,729,433	$ 1,445	1,174,142	581,244	(27,398)
Beginning balance, shares at Dec. 31, 2020	143,396	143,396
Beginning balance at Dec. 31, 2020	$ 1,739,907	$ 1,434	1,190,001	565,270	(16,798)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	401,293			401,293
Other comprehensive income (loss)	(3,745)				(3,745)
Purchase and retirement of common stock, shares		(5,218)
Purchase and retirement of common stock	(316,053)	$ (53)	(30,979)	(285,021)
Issuance of common stock under employee stock purchase plan, shares		64
Issuance of common stock under employee stock purchase plan	3,225	$ 1	3,224
Issuance of common stock upon exercise of stock options, shares		1,063
Issuance of common stock upon exercise of stock options	34,677	$ 11	34,666
Stock-based compensation	31,173		31,173
Dividends declared	$ (52,389)			(52,389)
Ending balance, shares at Sep. 30, 2021	139,305	139,305
Ending balance at Sep. 30, 2021	$ 1,838,088	$ 1,393	1,228,085	629,153	(20,543)
Beginning balance, shares at Jun. 30, 2021		141,027
Beginning balance at Jun. 30, 2021	1,805,606	$ 1,410	1,219,487	599,231	(14,522)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	138,045			138,045
Other comprehensive income (loss)	(6,021)				(6,021)
Purchase and retirement of common stock, shares		(1,980)
Purchase and retirement of common stock	(119,895)	$ (21)	(11,751)	(108,123)
Issuance of common stock under employee stock purchase plan, shares		22
Issuance of common stock under employee stock purchase plan	1,120	$ 1	1,119
Issuance of common stock upon exercise of stock options, shares		236
Issuance of common stock upon exercise of stock options	7,915	$ 3	7,912
Stock-based compensation	$ 11,318		11,318
Ending balance, shares at Sep. 30, 2021	139,305	139,305
Ending balance at Sep. 30, 2021	$ 1,838,088	$ 1,393	$ 1,228,085	$ 629,153	$ (20,543)

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Equity (Unaudited) (Parenthetical) - $ / shares	Jun. 02, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Stockholders' Equity [Abstract]
Dividends declared per common share (in USD per share)	$ 0.37	$ 0	$ 0	$ 0.37	$ 0.35

Consolidated Condensed Statemen

Consolidated Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net income	$ 401,293	$ 321,404
Adjustments to reconcile net income to net cash provided by operating activities (See Note 1)	82,588	75,120
Net cash provided by operating activities	483,881	396,524
Cash flows from investing activities:
Additions to property and equipment	(22,520)	(43,113)
Additions to capitalized software	(19,486)	(18,640)
Purchases of marketable securities	(168,333)	(114,407)
Prepayments and maturities of marketable securities	133,895	112,575
Sales of marketable securities	327	842
Other investing activities	(11,425)	(1,500)
Net cash used in investing activities	(87,542)	(64,243)
Cash flows from financing activities:
Payment of contingent consideration	(3,965)	(633)
Purchase and retirement of common stock	(315,811)	(327,079)
Proceeds from issuance of common stock	37,902	29,793
Payment of dividends	(105,516)	(103,914)
Net cash used in financing activities	(387,390)	(401,833)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(2,442)	(4,196)
Net increase (decrease) in cash, cash equivalents and restricted cash	6,507	(73,748)
Cash, cash equivalents and restricted cash, beginning of period	787,727	844,547
Cash, cash equivalents and restricted cash, end of period	$ 794,234	$ 770,799

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Nature of Operations SEI Investments Company (the Company), a Pennsylvania corporation, provides comprehensive platforms, services and infrastructure—encompassing technology, operational, and investment management services—to help wealth managers, financial advisors, investment managers, family offices, institutional and private investors create and manage wealth. Investment processing platforms provide technologies and business process outsourcing services for wealth managers and investment advisors. These solutions include investment advisory, client relationship, and other technology-enabled capabilities for the front office; administrative and investment services for the middle office; and accounting and processing services for the back office. Revenues from investment processing platforms are recognized in Information processing and software servicing fees on the accompanying Consolidated Statements of Operations. Investment operations platforms provide business process outsourcing services for investment managers and asset owners. These platforms support a broad range of traditional and alternative investments and provide technology-enabled information analytics and investor capabilities for the front office; administrative and investment services for the middle office; and fund administration and accounting services for the back office. Revenues from investment operations platforms are recognized in Asset management, administration and distribution fees on the accompanying Consolidated Statements of Operations. Investment management platforms provide comprehensive solutions for managing personal and institutional wealth. These platforms include goals-based investment strategies; SEI-sponsored investment products, including mutual funds, collective investment products, alternative investment portfolios and separately managed accounts (SMA); and other market-specific advice, technology and operational components. These platforms are offered to wealth managers as part of a complete goals-based investment program for their end-investors. For institutional investors, the Company provides Outsourced Chief Investment Officer (OCIO) solutions that include investment management programs, as well as advisory and administrative services. Revenues from investment management platforms 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 have 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 September 30, 2021, the results of operations for the three and nine months ended September 30, 2021 and 2020, and cash flows for the nine-months ended September 30, 2021 and 2020. 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, 2020. There have been no significant changes in significant accounting policies during the nine months ended September 30, 2021 as compared to the significant accounting policies described in the Company's Annual Report on Form 10-K for the year ended December 31, 2020. Variable Interest Entities The Company or its affiliates have 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. The Company receives asset management, distribution, administration and custodial fees for these services. Clients are the equity investors and participate in proportion to their ownership percentage in the net income or loss and net capital gains or losses of the products, and, on liquidation, will participate in proportion to their ownership percentage in the remaining net assets of the products after satisfaction of outstanding liabilities. The Company has concluded that it is not the primary beneficiary of the entities and, therefore, is not required to consolidate any of the pooled investment vehicles for which it receives asset management, distribution, administration and custodial fees under the VIE model. The Company is a party to expense limitation agreements with certain SEI-sponsored money market funds subject to Rule 2a-7 of the Investment Company Act of 1940 which establish a maximum level of ordinary operating expenses incurred by the fund in any fiscal year including, but not limited to, fees of the administrator or its affiliates. Under the terms of these agreements, the Company waived $11,629 and $8,575 in fees during the three months ended September 30, 2021 and 2020, respectively. During the nine months ended September 30, 2021 and 2020, the Company waived $33,118 and $24,930, respectively, in fees. Revenue Recognition Revenue is recognized when the transfer of control of promised goods or services under the terms of a contract with customers are satisfied in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those promised goods or services. Certain portions of the Company’s revenues involve a third party in providing goods or services to its customers. In such circumstances, the Company must determine whether the nature of its promise to the customer is to provide the underlying goods or services (the Company is the principal in the transaction and reports the transaction gross) or to arrange for a third party to provide the underlying goods or services (the entity is the agent in the transaction and reports the transaction net). See Note 13 for related disclosures regarding revenue recognition. Cash and Cash Equivalents Cash and cash equivalents includes $332,657 and $347,082 at September 30, 2021 and December 31, 2020, respectively, primarily invested in SEI-sponsored open-ended money market mutual funds. Restricted Cash Restricted cash includes $250 and $3,000 at September 30, 2021 and December 31, 2020, respectively, segregated for regulatory purposes related to trade-execution services conducted by SEI Investments (Europe) Limited. Restricted cash also includes $101 at September 30, 2021 and December 31, 2020 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 (SEC) for broker-dealers. Capitalized Software The Company capitalized $19,486 and $18,640 of software development costs during the nine months ended September 30, 2021 and 2020, respectively. The Company's software development costs primarily relate to significant enhancements to the SEI Wealth Platform SM (SWP). The Company capitalized $19,387 and $17,208 of software development costs for significant enhancements to SWP during the nine months ended September 30, 2021 and 2020, respectively. As of September 30, 2021, the net book value of SWP was $241,262 . The net book value includes $22,702 of capitalized software development costs in-progress associated with future releases of SWP. Capitalized software development costs in-progress associated with future releases of SWP were $13,409 as of December 31, 2020. SWP has a weighted average remaining life of 10.0 years. Amortization expense for SWP was $35,834 and $32,576 during the nine months ended September 30, 2021 and 2020, respectively. Earnings per Share The calculations of basic and diluted earnings per share for the three and nine months ended September 30, 2021 and 2020 are: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Net income $ 138,045 $ 111,096 $ 401,293 $ 321,404 Shares used to compute basic earnings per common share 140,507,000 145,812,000 141,928,000 147,586,000 Dilutive effect of stock options 1,919,000 2,095,000 2,053,000 2,372,000 Shares used to compute diluted earnings per common share 142,426,000 147,907,000 143,981,000 149,958,000 Basic earnings per common share $ 0.98 $ 0.76 $ 2.83 $ 2.18 Diluted earnings per common share $ 0.97 $ 0.75 $ 2.79 $ 2.14 During the three months ended September 30, 2021 and 2020, employee stock options to purchase 11,347,000 and 8,813,000 shares of common stock with an average exercise price of $57.80 and $57.98, respectively, were outstanding but not included in the computation of diluted earnings per common share. During the nine months ended September 30, 2021 and 2020, employee stock options to purchase 11,531,000 and 8,342,000 shares of common stock with an average exercise price of $57.78 and $58.18, respectively, were outstanding but not included in the computation of diluted earnings per common share. These options for the three and nine month periods were not included in the computation of diluted earnings per common share because either the performance conditions have not been satisfied or would not have been satisfied if the reporting date was the end of the contingency period or the options' exercise price was greater than the average market price of the Company’s common stock and the effect on diluted earnings per common share would have been anti-dilutive. Reclassifications Certain prior year amounts have been reclassified to conform to current year presentation. 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 nine months ended September 30: 2021 2020 Net income $ 401,293 $ 321,404 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation 25,141 23,058 Amortization 43,749 39,417 Equity in earnings of unconsolidated affiliate (103,420) (86,488) Distributions received from unconsolidated affiliate 110,559 107,180 Stock-based compensation 31,173 20,458 Provision for losses on receivables 1,569 109 Deferred income tax expense (6,639) (7,731) Net (gain) loss from investments (134) 1,310 Change in other long-term liabilities 2,103 (4,442) Change in other assets 314 (965) Contract costs capitalized, net of amortization (482) (2,842) Other 921 (1,053) Change in current assets and liabilities (Increase) decrease in Receivables from investment products (4,537) 2,521 Receivables (58,537) (37,921) Other current assets (3,919) (6,186) Advances due from unconsolidated affiliate 51,422 12,641 (Decrease) increase in Accounts payable 3,006 8,615 Accrued liabilities (9,851) 8,809 Deferred revenue 150 (1,370) Total adjustments 82,588 75,120 Net cash provided by operating activities $ 483,881 $ 396,524

Investment In Unconsolidated Af

Investment In Unconsolidated Affiliate	9 Months Ended
	Sep. 30, 2021
Equity Method Investments and Joint Ventures [Abstract]
Investment In Unconsolidated Affiliate	Investment in Unconsolidated Affiliate LSV Asset Management The Company has an investment in LSV Asset Management (LSV), a registered investment advisor that provides investment advisory services primarily to institutions, including pension plans and investment companies. LSV is currently an investment sub-advisor for a limited number of SEI-sponsored investment products. The Company's partnership interest in LSV as of September 30, 2021 was 38.7%. The Company accounts for its interest in LSV using the equity method because of its less than 50% 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 September 30, 2021, the Company’s total investment in LSV was $39,872. The Company receives partnership distributions from LSV on a quarterly basis. The Company received partnership distributions from LSV of $110,559 and $107,180 in the nine months ended September 30, 2021 and 2020, respectively. As such, the Company considers these distribution payments as returns on investment rather than returns of the Company's original investment in LSV and has therefore classified the associated cash inflows as an operating activity on the Consolidated Statements of Cash Flows. The Company’s proportionate share in the earnings of LSV was $35,005 and $28,305 during the three months ended September 30, 2021 and 2020, respectively. During the nine months ended September 30, 2021 and 2020, the Company's proportionate share in the earnings of LSV was $103,420 and $86,488, respectively. These tables contain condensed financial information of LSV: Condensed Statement of Operations Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Revenues $ 115,728 $ 94,902 $ 342,957 $ 289,546 Net income 90,365 70,440 266,805 220,184 Condensed Balance Sheets September 30, 2021 December 31, 2020 Current assets $ 123,325 $ 151,515 Non-current assets 4,426 4,296 Total assets $ 127,751 $ 155,811 Current liabilities $ 69,349 $ 77,077 Non-current liabilities 4,058 4,620 Partners’ capital 54,344 74,114 Total liabilities and partners’ capital $ 127,751 $ 155,811 On April 1, 2021, LSV provided an interest in the partnership to select key employees which reduced the ownership percentage of each existing partner on a pro-rata basis. As a result, the Company's total partnership interest in LSV was reduced slightly to approximately 38.7% from approximately 38.8%.

Composition of Certain Financia

Composition of Certain Financial Statement Captions	9 Months Ended
	Sep. 30, 2021
Items Included in Consolidated Statement of Financial Condition [Abstract]
Composition of Certain Financial Statement Captions	Composition of Certain Financial Statement Captions Receivables Receivables on the accompanying Consolidated Balance Sheets consist of: September 30, 2021 December 31, 2020 Trade receivables $ 112,572 $ 99,106 Fees earned, not billed 313,883 262,167 Other receivables 18,401 25,046 444,856 386,319 Less: Allowance for doubtful accounts (2,669) (1,100) $ 442,187 $ 385,219 Fees earned, not billed represents receivables from contracts with customers earned but unbilled and results from timing differences between services provided and contractual billing schedules. These billing schedules generally provide for fees to be billed on a quarterly basis. In addition, certain fees earned from investment operations services are calculated based on assets under administration that have an extended valuation process. Billings to these clients occur once the asset valuation processes are completed. Receivables from investment products on the accompanying Consolidated Balance Sheets primarily represent fees receivable for distribution, investment advisory, and administration services to various regulated investment companies and other investment products sponsored by SEI. Property and Equipment Property and Equipment on the accompanying Consolidated Balance Sheets consists of: September 30, 2021 December 31, 2020 Buildings $ 209,315 $ 206,151 Equipment 150,945 141,820 Land 24,651 24,179 Purchased software 156,327 147,838 Furniture and fixtures 21,196 21,439 Leasehold improvements 21,838 21,604 Construction in progress 209 4,660 584,481 567,691 Less: Accumulated depreciation (400,679) (378,639) Property and Equipment, net $ 183,802 $ 189,052 The Company recognized $25,141 and $23,058 in depreciation expense related to property and equipment for the nine months ended September 30, 2021 and 2020, respectively. Deferred Contract Costs Deferred contract costs, which primarily consist of deferred sales commissions, were $34,263 and $33,781 as of September 30, 2021 and December 31, 2020, respectively. The Company deferred expenses related to contract costs of $2,932 and $2,521 during the three months ended September 30, 2021 and 2020, respectively. During the nine months ended September 30, 2021 and 2020, the Company deferred expenses related to contract costs of $6,978 and $7,270, respectively. Amortization expense related to deferred contract costs were $6,496 and $4,428 during the nine months ended September 30, 2021 and 2020, respectively, and are included in Compensation, benefits and other personnel on the accompanying Consolidated Statements of Operations. There was no impairment loss in relation to deferred contract costs during the nine months ended September 30, 2021. Accrued Liabilities Accrued liabilities on the accompanying Consolidated Balance Sheets consist of: September 30, 2021 December 31, 2020 Accrued employee compensation $ 86,924 $ 95,656 Accrued employee benefits and other personnel 11,743 18,770 Accrued consulting, outsourcing and professional fees 35,945 31,907 Accrued sub-advisory, distribution and other asset management fees 57,560 49,924 Accrued dividend payable — 53,127 Other accrued liabilities 38,871 50,461 Total accrued liabilities $ 231,043 $ 299,845

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The fair value of the Company’s financial assets and liabilities, except for the Company's investment funds sponsored by LSV, is determined in accordance with the fair value hierarchy. The fair value of the Company’s Level 1 financial assets consist mainly of investments in open-ended mutual funds that are quoted daily. Level 2 financial assets consist of GNMA mortgage-backed securities held by the Company's wholly-owned limited purpose federal thrift subsidiary, SEI Private Trust Company (SPTC), Federal Home Loan Bank (FHLB) and other U.S. government agency short-term notes held by SIDCO. The financial assets held by SIDCO were purchased as part of a cash management program requiring only short term, top-tier investment grade government and corporate securities. The financial assets held by SPTC are debt securities issued by GNMA and are backed by the full faith and credit of the U.S. government. These securities were purchased for the sole purpose of satisfying applicable regulatory requirements and have maturity dates which range from 2023 to 2041. The fair value of the Company's investment funds sponsored by LSV is measured using the net asset value per share (NAV) as a practical expedient. The NAVs of the funds are calculated by the funds' independent custodian and are derived from the fair values of the underlying investments as of the reporting date. The funds allow for investor redemptions at the end of each calendar month. This investment has not been classified in the fair value hierarchy but is presented in the tables below to permit reconciliation to the amounts presented on the accompanying Consolidated Balance Sheets. The valuation of the Company's Level 2 financial assets held by SIDCO and SPTC are based upon securities pricing policies and procedures utilized by third-party pricing vendors. The pricing policies and procedures applied for our Level 1 and Level 2 financial assets during the nine months ended September 30, 2021 were consistent with those as described in the Company's Annual Report on Form 10-K at December 31, 2020. The Company had no Level 3 financial assets at September 30, 2021 or December 31, 2020 that were required to be measured at fair value on a recurring basis. Level 3 financial liabilities at September 30, 2021 and December 31, 2020 consist entirely of the estimated contingent consideration resulting from an acquisition (See Note 12). The fair value of the contingent consideration was determined using a Monte-Carlo simulation model. Key assumptions for the Monte-Carlo simulation model include expected revenues, expected volatility, risk-free rate and other factors. There were no transfers of financial assets between levels within the fair value hierarchy during the nine months ended September 30, 2021. The fair value of certain financial assets of the Company was determined using the following inputs: Fair Value Measurements at the End of the Reporting Period Using Assets September 30, 2021 Quoted Prices in Significant Equity securities $ 12,241 $ 12,241 $ — Available-for-sale debt securities 127,838 — 127,838 Fixed-income securities owned 31,770 — 31,770 Investment funds sponsored by LSV (1) 6,893 $ 178,742 $ 12,241 $ 159,608 Fair Value Measurements at the End of the Reporting Period Using Assets December 31, 2020 Quoted Prices in Significant Equity securities $ 12,142 $ 12,142 $ — Available-for-sale debt securities 93,277 — 93,277 Fixed-income securities owned 34,064 — 34,064 Investment funds sponsored by LSV (1) 6,166 $ 145,649 $ 12,142 $ 127,341

Marketable Securities

Marketable Securities	9 Months Ended
	Sep. 30, 2021
Marketable Securities [Abstract]
Marketable Securities	Marketable Securities Marketable securities include investments in money market funds and commercial paper classified as cash equivalents, available-for-sale debt securities, investments in SEI-sponsored and non-SEI-sponsored mutual funds, equities, investments in funds sponsored by LSV and securities owned by SIDCO. Cash Equivalents Investments in money market funds and commercial paper classified as cash equivalents had a fair value of $453,628 and $462,624 at September 30, 2021 and December 31, 2020, respectively. There were no material unrealized or realized gains or losses from these investments during the nine months ended September 30, 2021 and 2020. Investments in money market funds and commercial paper are Level 1 assets. Available for Sale and Equity Securities Available For Sale and Equity Securities on the accompanying Consolidated Balance Sheets consist of: At September 30, 2021 Cost Gross Gross Fair Available-for-sale debt securities $ 126,964 $ 874 $ — $ 127,838 SEI-sponsored mutual funds 6,692 380 — 7,072 Equities and other mutual funds 4,932 237 — 5,169 $ 138,588 $ 1,491 $ — $ 140,079 At December 31, 2020 Cost Gross Gross Fair Available-for-sale debt securities $ 91,262 $ 2,015 $ — $ 93,277 SEI-sponsored mutual funds 6,866 382 — 7,248 Equities and other mutual funds 4,421 473 — 4,894 $ 102,549 $ 2,870 $ — $ 105,419 Net unrealized gains at September 30, 2021 of available-for-sale debt securities were $673 (net of income tax expense of $201). Net unrealized gains at December 31, 2020 of available-for-sale debt securities were $1,551 (net of income tax expense of $464). These net unrealized gains are reported as a separate component of Accumulated other comprehensive loss on the accompanying Consolidated Balance Sheets. There were gross realized losses of $861 and $582 from available-for-sale debt securities during the nine months ended September 30, 2021 and 2020, respectively. There were no gross realized gains from available-for-sale debt securities during the nine months ended September 30, 2021 and 2020. Realized losses from available-for-sale debt securities, including amounts reclassified from accumulated comprehensive loss, are reflected in Net (loss) gain from investments on the accompanying Consolidated Statements of Operations. There were gross realized gains of $714 and gross realized losses of $65 from mutual funds and equities during the nine months ended September 30, 2021. There were gross realized gains of $254 and gross realized losses of $250 from mutual funds and equities during the nine months ended September 30, 2020. Gains and losses from mutual funds and equities are reflected in Net (loss) gain from investments on the accompanying Consolidated Statements of Operations. Investments in Affiliated Funds The Company has an investment in funds sponsored by LSV. The Company records this investment on the accompanying Consolidated Balance Sheets at fair value. Unrealized gains and losses from the change in fair value of these funds are recognized in Net (loss) gain from investments on the accompanying Consolidated Statements of Operations. The funds had a fair value of $6,893 and $6,166 at September 30, 2021 and December 31, 2020, respectively. The Company recognized unrealized losses of $39 and unrealized gains of $458 during the three months ended September 30, 2021 and 2020, respectively, from the change in fair value of the funds. The Company recognized unrealized gains of $727 and unrealized losses of $781 during the nine months ended September 30, 2021 and 2020, respectively, from the change in fair value of the funds. Securities Owned The Company’s broker-dealer subsidiary, SIDCO, has investments in U.S. government agency 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 $31,770 and $34,064 at September 30, 2021 and December 31, 2020, respectively. There were no material net gains or losses related to the securities during the three and nine months ended September 30, 2021 and 2020.

Line of Credit

Line of Credit	9 Months Ended
	Sep. 30, 2021
Line of Credit Facility [Abstract]
Line of Credit	Line of Credit On April 23, 2021 (the Closing Date), the Company entered into a new five-year $325,000 Credit Agreement (the Credit Facility) with Wells Fargo Bank, N.A., and a syndicate of other lenders. The Credit Facility became available on the Closing Date and replaced the former credit facility agreement (the 2016 Credit Facility). The Credit Facility is scheduled to expire in April 2026, 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 rates that, at the Company's option, are based on a base rate (the Base Rate) plus a premium that can range from 0.25% to 1.00% or the London InterBank Offered Rate (LIBOR) plus a premium that can range from 1.25% to 2.00% depending on the Company’s Leverage Ratio (a ratio of consolidated indebtedness to consolidated EBITDA for the four preceding fiscal quarters, all as defined in the related agreement). The Base Rate is defined as the highest of a) the Federal Funds Rate, as published by the Federal Reserve Bank of New York, plus 0.50%, b) the prime commercial lending rate of Wells Fargo, c) the applicable LIBOR plus 1.00%, or d) 0%. The Credit Facility includes fallback language clearly defining an alternative reference rate which provides for specified replacement rates upon a LIBOR cessation event. At the time of a LIBOR cessation event, the replacement rate, the Secured Overnight Financing Rate (SOFR), self-executes without the need for negotiations or a formal amendment process. The Company also pays quarterly commitment fees based on the unused portion of the Credit Facility. The quarterly fees for the Credit Facility can range from 0.15% of the amount of the unused portion to 0.30%, depending on the Company’s Leverage Ratio. Certain wholly-owned subsidiaries of the Company have guaranteed the obligations of the Company under the agreement. The aggregate amount of the Credit Facility may be increased by an additional $100,000 under certain conditions set forth in the agreement. The Company may issue up to $15,000 in letters of credit under the terms of the Credit Facility. The Company pays a periodic commission fee of 1.25% plus an issuance fee of 0.200% of the aggregate face amount of the outstanding letters of credit issued under the Credit Facility. The Credit Facility contains covenants with restrictions on the ability of the Company to do transactions with affiliates other than wholly-owned subsidiaries or to incur liens or certain types of indebtedness 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. 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. As of September 30, 2021, the Company had outstanding letters of credit of $5,808 under the Credit Facility. These letters of credit were issued primarily for the expansion of the Company's headquarters and are scheduled to expire during 2021. The amount of the Credit Facility that is available for general corporate purposes as of September 30, 2021 was $319,192. The Company was in compliance with all covenants of the credit facilities during the nine months ended September 30, 2021.

Shareholders' Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2021
Stockholders' Equity Note [Abstract]
Shareholders' Equity	Shareholders’ Equity Stock-Based Compensation The Company has only non-qualified stock options outstanding under its equity compensation plans. 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% when a specified financial vesting target is achieved, and the remaining 50% when a second, higher specified financial vesting target is achieved. Options vest as a result of achievement of the financial vesting targets. Options granted in December 2017 and thereafter include a service condition which requires a minimum two estimate of when the financial vesting targets may be achieved. Any change in management’s estimate could result in the remaining amount of stock-based compensation expense to be accelerated, spread out over a longer period, or reversed. This may cause volatility in the recognition of stock-based compensation expense in future periods and could materially affect the Company’s earnings. The Company recognized stock-based compensation expense in its Consolidated Financial Statements in the three and nine months ended September 30, 2021 and 2020, respectively, as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Stock-based compensation expense $ 11,318 $ 6,467 $ 31,173 $ 20,458 Less: Deferred tax benefit (1,857) (1,229) (5,615) (3,932) Stock-based compensation expense, net of tax $ 9,461 $ 5,238 $ 25,558 $ 16,526 The Company revised its estimates of when some vesting targets are expected to be achieved during 2021 and 2020. The change in management's estimate during the nine months ended September 30, 2021 resulted in an increase of $3,209 in stock-based compensation expense. The change in estimate during the nine months ended September 30, 2020 did not result in a material change to the Company's stock-based compensation expense. As of September 30, 2021, there was approximately $72,399 of unrecognized compensation cost remaining related to unvested employee stock options that management expects will vest and is being amortized. The Company issues new common shares associated with the exercise of stock options. The total intrinsic value of options exercised during the nine months ended September 30, 2021 was $30,496. The total options exercisable as of September 30, 2021 had an intrinsic value of $104,146. The total intrinsic value for options exercisable is calculated as the difference between the market value of the Company’s common stock as of September 30, 2021 and the weighted average exercise price of the options. The market value of the Company’s common stock as of September 30, 2021 was $59.30 as reported by the Nasdaq Stock Market, LLC. The weighted average exercise price of the options exercisable as of September 30, 2021 was $40.63. Total options that were outstanding as of September 30, 2021 were 16,925,000 . Total options that were exercisable as of September 30, 2021 were 5,578,000 . Common Stock Buyback The Company’s Board of Directors, under multiple authorizations, has authorized the repurchase of common stock on the open market or through private transactions. The Company purchased 5,218,000 shares at a total cost of $316,053 during the nine months ended September 30, 2021, which reduced the total shares outstanding of common stock. The cost of stock purchases during the period includes the cost of certain transactions that settled in the following quarter. As of September 30, 2021, the Company had approximately $126,775 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. Cash Dividend On June 2, 2021, the Board of Directors declared a cash dividend of $0.37 per share on the Company's common stock, which was paid on June 22, 2021, to shareholders of record on June 14, 2021. Cash dividends declared during the nine months ended September 30, 2021 and 2020 were $52,389 and $51,462, respectively.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	9 Months Ended
	Sep. 30, 2021
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss The components of Accumulated other comprehensive loss, net of tax, are as follows: Foreign Currency Translation Adjustments Unrealized Accumulated Other Comprehensive Loss Balance, January 1, 2021 $ (18,349) $ 1,551 $ (16,798) Other comprehensive loss before reclassifications (2,867) (1,548) (4,415) Amounts reclassified from accumulated other comprehensive loss — 670 670 Net current-period other comprehensive loss (2,867) (878) (3,745) Balance, September 30, 2021 $ (21,216) $ 673 $ (20,543)

Business Segment Information

Business Segment Information	9 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Business Segment Information	Business Segment Information The Company’s reportable business segments are: Private Banks – Provides outsourced investment processing and investment management platforms to banks and trust institutions, independent wealth advisers and financial advisors worldwide; Investment Advisors – Provides investment management and investment processing platforms to affluent investors through a network of independent registered investment advisors, financial planners and other investment professionals in the United States; Institutional Investors – Provides OCIO solutions, including investment management and administrative outsourcing platforms to retirement plan sponsors, healthcare systems, higher education and other not-for-profit organizations worldwide; Investment Managers – Provides investment operations outsourcing platforms to fund companies, banking institutions, traditional and non-traditional investment managers worldwide and family offices in the United States; and Investments in New Businesses – Focuses on providing investment management solutions to ultra-high-net-worth families residing in the United States; developing network and data protection services; modularizing larger technology platforms into stand-alone components; entering new markets; and conducting other research and development activities. The information in the following tables is derived from internal financial reporting used for corporate management purposes. There are no inter-segment revenues for the three and nine months ended September 30, 2021 and 2020. 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, 2020. The following tables highlight certain financial information about each of the business segments for the three months ended September 30, 2021 and 2020: Private Banks Investment Institutional Investment Investments Total For the Three Months Ended September 30, 2021 Revenues $ 123,018 $ 124,768 $ 85,759 $ 147,412 $ 4,365 $ 485,322 Expenses 116,679 62,107 41,643 89,594 12,820 322,843 Operating profit (loss) $ 6,339 $ 62,661 $ 44,116 $ 57,818 $ (8,455) $ 162,479 Private Investment Institutional Investment Investments Total For the Three Months Ended September 30, 2020 Revenues $ 114,792 $ 103,189 $ 79,583 $ 123,846 $ 3,517 $ 424,927 Expenses 113,066 51,519 37,812 79,838 13,315 295,550 Operating profit (loss) $ 1,726 $ 51,670 $ 41,771 $ 44,008 $ (9,798) $ 129,377 A reconciliation of the total operating profit reported for the business segments to income from operations in the Consolidated Statements of Operations for the three months ended September 30, 2021 and 2020 is as follows: 2021 2020 Total operating profit from segments $ 162,479 $ 129,377 Corporate overhead expenses (21,354) (18,040) Income from operations $ 141,125 $ 111,337 The following tables provide additional information for the three months ended September 30, 2021 and 2020 pertaining to the business segments: Capital Expenditures (1) Depreciation 2021 2020 2021 2020 Private Banks $ 6,173 $ 7,652 $ 4,980 $ 4,222 Investment Advisors 2,896 3,234 499 1,255 Institutional Investors 720 698 271 298 Investment Managers 3,722 2,776 2,428 1,818 Investments in New Businesses 336 144 60 97 Total from business segments $ 13,847 $ 14,504 $ 8,238 $ 7,690 Corporate overhead 419 274 170 255 $ 14,266 $ 14,778 $ 8,408 $ 7,945 (1) Capital expenditures include additions to property and equipment and capitalized software. Amortization 2021 2020 Private Banks $ 8,526 $ 7,505 Investment Advisors 3,014 2,683 Institutional Investors 427 426 Investment Managers 2,451 2,343 Investments in New Businesses 185 186 Total from business segments $ 14,603 $ 13,143 Corporate overhead 71 57 $ 14,674 $ 13,200 The following tables highlight certain financial information about each of business segment for the nine months ended September 30, 2021 and 2020: Private Investment Institutional Investment Investments Total For the Nine Months Ended September 30, 2021 Revenues $ 364,302 $ 357,458 $ 255,957 $ 426,639 $ 12,303 $ 1,416,659 Expenses 345,057 176,267 122,696 257,609 39,855 941,484 Operating profit (loss) $ 19,245 $ 181,191 $ 133,261 $ 169,030 $ (27,552) $ 475,175 Private Investment Institutional Investment Investments Total For the Nine Months Ended September 30, 2020 Revenues $ 335,739 $ 299,218 $ 235,309 $ 359,815 $ 10,254 $ 1,240,335 Expenses 331,442 154,100 113,016 228,795 37,691 865,044 Operating profit (loss) $ 4,297 $ 145,118 $ 122,293 $ 131,020 $ (27,437) $ 375,291 A reconciliation of the total operating profit reported for the business segments to income from operations in the Consolidated Statements of Operations for the nine months ended September 30, 2021 and 2020: 2021 2020 Total operating profit from segments $ 475,175 $ 375,291 Corporate overhead expenses (65,192) (53,414) Income from operations $ 409,983 $ 321,877 The following tables provide additional information for the nine months ended September 30, 2021 and 2020: Capital Expenditures (1) Depreciation 2021 2020 2021 2020 Private Banks $ 20,596 $ 24,211 $ 13,290 $ 12,069 Investment Advisors 8,784 12,427 3,205 3,578 Institutional Investors 2,115 3,085 982 901 Investment Managers 8,726 19,067 6,508 5,499 Investments in New Businesses 788 894 306 243 Total from business segments $ 41,009 $ 59,684 $ 24,291 $ 22,290 Corporate Overhead 997 2,069 850 768 $ 42,006 $ 61,753 $ 25,141 $ 23,058 (1) Capital expenditures include additions to property and equipment and capitalized software. Amortization 2021 2020 Private Banks $ 25,735 $ 22,390 Investment Advisors 8,550 7,999 Institutional Investors 1,280 1,280 Investment Managers 7,375 7,020 Investments in New Businesses 555 556 Total from business segments $ 43,495 $ 39,245 Corporate Overhead 254 172 $ 43,749 $ 39,417

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income TaxesThe gross liability for unrecognized tax benefits at September 30, 2021 and December 31, 2020 was $16,721 and $15,911, respectively, exclusive of interest and penalties, of which $16,532 and $15,761 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 September 30, 2021 and December 31, 2020, the combined amount of accrued interest and penalties related to tax positions taken on tax returns was $1,835 and $2,105, respectively. September 30, 2021 December 31, 2020 Gross liability for unrecognized tax benefits, exclusive of interest and penalties $ 16,721 $ 15,911 Interest and penalties on unrecognized benefits 1,835 2,105 Total gross uncertain tax positions $ 18,556 $ 18,016 Amount included in Current liabilities $ 4,497 $ 6,546 Amount included in Other long-term liabilities 14,059 11,470 $ 18,556 $ 18,016 The effective income tax rate for the three and nine months ended September 30, 2021 and 2020 differs from the federal income tax statutory rate due to the following: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Statutory rate 21.0 % 21.0 % 21.0 % 21.0 % State taxes, net of federal tax benefit 2.5 3.3 3.0 3.2 Foreign tax expense and tax rate differential (0.1) (0.2) (0.1) (0.1) Tax benefit from stock option exercises (0.6) (0.4) (1.0) (1.0) Expiration of the statute of limitations — (1.3) — (0.5) State settlements (0.3) — (0.2) — Provision-to-return adjustment (0.5) (0.4) (0.2) (0.1) Other, net (0.3) (0.6) (0.3) (0.5) 21.7 % 21.4 % 22.2 % 22.0 % 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 2017 and is no longer subject to state, local or foreign income tax examinations by authorities for years before 2015. The Company estimates it will recognize $4,497 of gross unrecognized tax benefits. This amount is expected to be paid within one year or to be removed at the expiration of the statute of limitations and resolution of income tax audits and is netted against the current payable account. 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 the 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.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies In the ordinary course of business, the Company from time to time enters into contracts containing indemnification obligations of the Company. These obligations may require the Company to make payments to another party upon the occurrence of certain events including the failure by the Company to meet its performance obligations under the contract. These contractual indemnification provisions are often standard contractual terms of the nature customarily found in the type of contracts entered into by the Company. In many cases, there are no stated or notional amounts included in the indemnification provisions. There are no amounts reflected on the Consolidated Balance Sheets as of September 30, 2021 and December 31, 2020 related to these indemnifications. Stanford Trust Company Litigation SEI has been named in seven lawsuits filed in Louisiana courts; four of the cases also name SPTC as a defendant. The underlying allegations in all actions relate to the purported role of SPTC in providing back-office services to Stanford Trust Company. The complaints allege that SEI and SPTC participated in some manner in the sale of “certificates of deposit” issued by Stanford International Bank so as to be a “seller” of the certificates of deposit for purposes of primary liability under the Louisiana Securities Law or so as to be secondarily liable under that statute for sales of certificates of deposit made by Stanford Trust Company. Two of the actions also include claims for violations of the Louisiana Racketeering Act and possibly conspiracy, and a third also asserts claims of negligence, breach of contract, breach of fiduciary duty, violations of the uniform fiduciaries law, negligent misrepresentation, detrimental reliance, violations of the Louisiana Racketeering Act, and conspiracy. The procedural status of the seven cases varies. The Lillie case, filed originally in the 19th Judicial District Court for the Parish of East Baton Rouge, was brought as a class action. A group of plaintiffs who opted out of the Lillie class filed a complaint against SEI and SPTC in the United States District Court in the Middle District of Louisiana, alleging claims essentially the same as those in Lillie. In both cases, as a result of the proceedings in the Northern District of Texas, only the plaintiffs’ secondary liability claims under Section 714(B) of the Louisiana Securities Law remain. On January 31, 2019, the Judicial Panel on Multidistrict Litigation remanded the Lillie and Ahders proceedings to the Middle District of Louisiana. With respect to the Lillie proceeding, on July 9, 2019, the District Court issued an order granting SEI’s Summary Judgment Motion to dismiss the remaining Section 714(B) claim and denying Plaintiffs’ Motion for Continuance of SEI and SPTC’s Motion for Summary Judgment pursuant to Rule 56(d). On August 27, 2019, Plaintiffs-Appellants filed a Notice of Appeal to the United States Court of Appeals for the Fifth Circuit of the District Court's dismissal of the Lillie matter. On May 14, 2021, the United States Court of Appeals for the Fifth Circuit unanimously affirmed the District Court’s order granting summary judgment in favor SEI and the Insurer Defendants in the Lillie matter. With respect to the Ahders proceeding, on January 24, 2020, the District Court issued an order granting SEI’s Summary Judgment Motion to dismiss the remaining Section 714(B) claim. On March 17, 2020, Plaintiffs-Appellants filed a Notice of Appeal to the United States Court of Appeals for the Fifth Circuit of the District Court's dismissal of the Ahders matter. On December 3, 2020, the United States Court of Appeals for the Fifth Circuit unanimously affirmed the District Court’s order granting summary judgment in favor of SEI and the Insurer Defendants in the Adhers matter. Another case, filed in the 23rd Judicial District Court for the Parish of Ascension, also was removed to federal court and transferred by the Judicial Panel on Multidistrict Litigation to the Northern District of Texas and the Stanford MDL. The schedule for responding to that Complaint has not yet been established. Two additional cases remain in the Parish of East Baton Rouge. Plaintiffs filed petitions in 2010 and have granted SEI and SPTC indefinite extensions to respond. No material activity has taken place since. In two additional cases, filed in East Baton Rouge and brought by the same counsel who filed the Lillie action, virtually all of the litigation to date has involved motions practice and appellate litigation regarding the existence of federal subject matter jurisdiction under the federal Securities Litigation Uniform Standards Act (SLUSA). The matters were removed to the United States District Court for the Northern District of Texas and consolidated. The court then dismissed the action under SLUSA. The Court of Appeals for the Fifth Circuit reversed that order, and the Supreme Court of the United States affirmed the Court of Appeals judgment on February 26, 2014. The matters were remanded to state court and no material activity has taken place since that date. While the outcome of this litigation remains uncertain, SEI and SPTC believe that they have valid defenses to plaintiffs' claims and intend to defend the lawsuits vigorously. Because of uncertainty in the make-up of the Lillie class, the specific theories of liability that may survive a motion for summary judgment or other dispositive motion, the relative 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. SS&C Advent Matter On February 28, 2020, SEI Global Services, Inc. (SGSI), a wholly-owned subsidiary of the Company, filed a complaint under seal in the United States District Court for the Eastern District of Pennsylvania against SS&C Advent (Advent) and SS&C Technologies Holdings, Inc. (SS&C) alleging that SS&C and Advent breached the terms of the contract between the parties and asking the Court to hold SS&C and Advent to their bargained-for obligations (the Advent Matter). In addition to Breach of Contract, the complaint also includes counts for Declaratory Judgment, Tortious Interference with Existing and Prospective Contractual Relations, Violation of the New York General Business Law Section 349, Violations of Section 2 of the Sherman Antitrust Act, Promissory Estoppel and Breach of the Covenant of Good Faith and Fair Dealing. SGSI seeks various forms of relief, including declaratory judgment, specific performance under the contract, and monetary damages, including treble damages and attorney’s fees. Following various procedural actions, including an amendment of SGSI’s complaint to include additional breach of contract claims, Advent filed a motion to dismiss SGSI’s complaint. On October 23, 2020, the United States District Court for the Eastern District of Pennsylvania dismissed SEI’s federal antitrust claims and declined to rule on the state law claims on the basis that in the absence of the anti-trust claim, the court had no jurisdiction over the state law claims. SGSI has appealed the dismissal of the federal anti-trust claims to the Third Circuit Court of Appeals, which is currently pending. Since October 23, 2020, Advent and SGSI have been litigating the remaining breach of contract and tortious interference with contract claims in New York State Court. Additionally, SGSI made motions for injunctive relief to insure that Advent provided SGSI with access to the Geneva, Moxy and APX software modules as SGSI believes is required pursuant to the terms of a valid contract. On January 13, 2021, Judge Borrok of the Supreme Court of the State of New York, granted SGSI’s motion for injunctive relief and issued an Order in which he characterized the basis for Advent’s claim for breach of contract as appearing to be “pre-textual” and found that SGSI’s claims for breach of contract would likely succeed on the merits. Judge Borrok granted SGSI’s motion for injunctive relief, on a preliminary basis, and precluded SS&C Advent from: • Dishonoring their contractual obligations and commitments under the SLSA, including, denying SEI’s licenses, rights, and privileges under the SLSA; • Failing to provide new license keys for the license keys due to Geneva, Moxy, and APX, and other software products licensed by SEI pursuant to the SLSA (such new license keys to be provided no later than January 15, 2021 at 10 A.M.); • Denying to SEI any and all access to the Geneva, Moxy, and APX software and related modules as are reasonably necessary to provide access to such software to SEI’s clients; and • Denying to SEI any and all support, maintenance and technical support services for Geneva, Moxy, and APX. SS&C Advent provided SEI with the necessary access to the Geneva, Moxy and APX software modules on January 14, 2021. These have been tested, verified and are now running in the SEI production environment. On January 15, 2021, SS&C Advent appealed Judge Borrok’s order granting SEI’s motion for preliminary injunctive relief to the Appellate Division of the Supreme Court of the State of New York, First Department. The Appellate Division affirmed the injunction order on June 15, 2021. On March 1, 2021, SS&C Advent moved to dismiss SGSI’s breach of contract and tortious interference with contract counter claims. These counter-claims were: 1. breach of contract, 2. declaratory judgment, 3. tortious interference with existing and prospective contractual relations, 4. deceptive trade practices in violation of NY Statutes, 5. breach of the covenant of good faith and fair dealing, and 6. promissory estoppel. The parties agreed to toll the litigation while endeavoring to resolve their dispute through a settlement mediation process moderated by Judge Borrock. The parties were unable to reach an agreement as to a settlement of the litigation and reengaged in the litigation process. On October 5, 2021, Judge Borrock issued an order partially denying and partially granting SS&C’s Advent’s motion to dismiss SGSI’s breach of contract and tortious interference with contract counter claims. Judge Borrock dismissed the third claim with respect to prospective contractual relationships only, as well as the fourth claim and the sixth claim. The remaining claims that will proceed are: 1. breach of contract, 2. declaratory judgment, 3. tortious interference with existing a contractual relations, and 4. breach of the covenant of good faith and fair dealing. We expect that the parties will also reengage with respect to SGSI’s pending appeal in the Third Circuit of the dismissal of SGSI’s anti-trust-claims. SEI continues to believe that it will have to change providers under the current terms of its contract with SS&C Advent and that the process of litigating its rights under this contract may be a multi-year process. Consequently, SEI does not believe that the Advent Matter will create any consequence to the services SGSI provides to its clients in the near term. SEI believes that it has alternatives available to it that will enable it to continue to provide currently provided services to its clients in all material respects in the unlikely event that there ultimately is a negative outcome in the Advent Matter. SEI believes SGSI has a strong basis for proving the actions it alleges in the Advent Matter and looks forward to the opportunity to continue to assert its rights under contract and prove the damages that it has suffered as a consequence of the behavior by SS&C Advent that SGSI alleges. SEI expects the financial impact of litigating the Advent Matter to be immaterial. Other Matters The Company and certain of its subsidiaries are party to various other examinations, investigations, actions and claims arising in the normal course of business that the Company does not believe are material. The Company believes that the ultimate resolution of these matters will not have a material adverse effect on the Company's financial position or the manner in which the Company conducts its business. Currently, the Company does not believe the amount of losses associated with these matters can be estimated. While the Company does not believe that the amount of such losses will, when liquidated or estimable, be material to its financial position, the assumptions may be incorrect and any such loss could have a material adverse effect on the Company's results of operations or the manner in which the Company conducts its business in the period(s) during which the underlying matters are resolved.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
	Sep. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets On April 2, 2018, the Company acquired all ownership interests of Huntington Steele, LLC (Huntington Steele). The total purchase price was allocated to Huntington Steele’s net tangible and intangible assets based upon their estimated fair values at the date of purchase. The excess purchase price over the value of the identifiable intangible assets was recorded as goodwill. The total amount of goodwill from this transaction amounted to $11,499 and is included on the accompanying Consolidated Balance Sheets. The total purchase price for Huntington Steele included a contingent purchase price payable to the sellers upon the attainment of specified financial measures determined at various intervals occurring between 2019 and 2023. The Company made payments of $3,965 and $633 during the nine months ended September 30, 2021 and 2020, respectively, to the sellers. As of September 30, 2021, the current portion of the contingent consideration of $765 is included in Accrued liabilities on the accompanying Balance Sheet. The long-term portion of the contingent consideration of $8,099 is included in Other long-term liabilities on the accompanying Balance Sheet. In July 2017, the Company acquired all ownership interests of Archway Technology Partners, LLC, Archway Finance & Operations, Inc. and Keystone Capital Holdings, LLC (collectively, Archway), a provider of operating technologies and services to the family office industry. The total purchase price was allocated to Archway’s net tangible and intangible assets based upon their estimated fair values at the date of purchase. The excess purchase price over the value of the net tangible and identifiable intangible assets was recorded as goodwill. The total amount of goodwill from this transaction amounted to $52,990 and is included on the accompanying Consolidated Balance Sheets. There were no changes to goodwill during the nine months ended September 30, 2021. The Company recognized $2,763 of amortization expense related to the intangible assets acquired through acquisitions of Huntington Steele and Archway during the nine months ended September 30, 2021 and 2020.

Revenues from Contracts with Cu

Revenues from Contracts with Customers	9 Months Ended
	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Revenues from Contracts with Customers	Revenues from Contracts with Customers The Company’s principal sources of revenues are: (1) asset management, administration and distribution fees primarily earned based upon a contractual percentage of net assets under management or administration; and (2) information processing and software servicing fees that are either recurring and primarily earned based upon the number of trust accounts being serviced or a percentage of the market value of the clients' assets processed on the Company's platforms, or non-recurring and based upon project-oriented contractual agreements related to client implementations. Disaggregation of Revenue The following tables provide additional information pertaining to our revenues disaggregated by major product line and primary geographic market based on the location of the use of the products or services for each of the business segments for the three months ended September 30, 2021 and 2020: Private Banks Investment Institutional Investment Investments Total Major Product Lines: For the Three Months Ended September 30, 2021 Investment management fees from pooled investment products $ 34,212 $ 77,123 $ 13,639 $ 32 $ 338 $ 125,344 Investment management fees from investment management agreements 605 41,688 71,964 — 3,864 118,121 Investment operations fees 363 — — 136,978 — 137,341 Investment processing fees - PaaS 54,191 — — — — 54,191 Investment processing fees - SaaS 28,579 — — 3,848 — 32,427 Professional services fees 4,174 — — 871 — 5,045 Account fees and other 894 5,957 156 5,683 163 12,853 Total revenues $ 123,018 $ 124,768 $ 85,759 $ 147,412 $ 4,365 $ 485,322 Primary Geographic Markets: United States $ 77,260 $ 124,768 $ 68,810 $ 136,934 $ 4,365 $ 412,137 United Kingdom 28,767 — 13,327 — — 42,094 Canada 12,343 — 926 — — 13,269 Ireland 4,648 — 2,570 10,478 — 17,696 Other — — 126 — — 126 Total revenues $ 123,018 $ 124,768 $ 85,759 $ 147,412 $ 4,365 $ 485,322 Private Investment Institutional Investment Investments Total Major Product Lines: For the Three Months Ended September 30, 2020 Investment management fees from pooled investment products $ 32,256 $ 68,287 $ 13,417 $ 180 $ 356 $ 114,496 Investment management fees from investment management agreements 421 29,761 65,811 — 3,041 99,034 Investment operations fees 446 — — 113,037 — 113,483 Investment processing fees - PaaS 47,393 — — — — 47,393 Investment processing fees - SaaS 27,567 — — 3,479 — 31,046 Professional services fees 5,663 — — 2,016 — 7,679 Account fees and other 1,046 5,141 355 5,134 120 11,796 Total revenues $ 114,792 $ 103,189 $ 79,583 $ 123,846 $ 3,517 $ 424,927 Primary Geographic Markets: United States $ 74,633 $ 103,189 $ 62,699 $ 116,196 $ 3,517 $ 360,234 United Kingdom 25,234 — 12,930 — — 38,164 Canada 10,596 — 1,298 — — 11,894 Ireland 4,329 — 2,526 7,650 — 14,505 Other — — 130 — — 130 Total revenues $ 114,792 $ 103,189 $ 79,583 $ 123,846 $ 3,517 $ 424,927 The following tables provide additional information pertaining to our revenues disaggregated by major product line and primary geographic market based on the location of the use of the products or services for each of the Company’s business segments for the nine months ended September 30, 2021 and 2020: Private Investment Institutional Investment Investments Total Major Product Lines: For the Nine Months Ended September 30, 2021 Investment management fees from pooled investment products $ 100,484 $ 224,816 $ 41,365 $ 105 $ 993 $ 367,763 Investment management fees from investment management agreements 1,681 114,747 213,249 — 10,811 340,488 Investment operations fees 1,134 — — 394,401 — 395,535 Investment processing fees - PaaS 160,813 — — — — 160,813 Investment processing fees - SaaS 84,831 — — 11,409 — 96,240 Professional services fees 12,509 — — 2,885 — 15,394 Account fees and other 2,850 17,895 1,343 17,839 499 40,426 Total revenues $ 364,302 $ 357,458 $ 255,957 $ 426,639 $ 12,303 $ 1,416,659 Primary Geographic Markets: United States $ 231,203 $ 357,458 $ 203,322 $ 396,598 $ 12,303 $ 1,200,884 United Kingdom 83,514 — 41,091 — — 124,605 Canada 35,977 — 3,426 — — 39,403 Ireland 13,608 — 7,735 30,041 — 51,384 Other — — 383 — — 383 Total revenues $ 364,302 $ 357,458 $ 255,957 $ 426,639 $ 12,303 $ 1,416,659 Private Investment Institutional Investment Investments Total Major Product Lines: For the Nine Months Ended September 30, 2020 Investment management fees from pooled investment products $ 95,407 $ 200,718 $ 39,628 $ 536 $ 1,063 $ 337,352 Investment management fees from investment management agreements 1,060 83,726 194,445 — 8,912 288,143 Investment operations fees 1,359 — — 328,316 — 329,675 Investment processing fees - PaaS 137,737 — — — — 137,737 Investment processing fees - SaaS 84,783 — — 10,122 — 94,905 Professional services fees 11,535 — — 4,674 — 16,209 Account fees and other 3,858 14,774 1,236 16,167 279 36,314 Total revenues $ 335,739 $ 299,218 $ 235,309 $ 359,815 $ 10,254 $ 1,240,335 Primary Geographic Markets: United States $ 220,254 $ 299,218 $ 185,202 $ 335,776 $ 10,254 $ 1,050,704 United Kingdom 71,938 — 38,034 — — 109,972 Canada 30,723 — 4,327 — — 35,050 Ireland 12,824 — 7,321 24,039 — 44,184 Other — — 425 — — 425 Total revenues $ 335,739 $ 299,218 $ 235,309 $ 359,815 $ 10,254 $ 1,240,335 Investment management fees from pooled investment products - Revenues associated with clients' assets invested in Company-sponsored pooled investment products. Contractual fees are stated as a percentage of the market value of assets under management and collected on a monthly basis. Revenues are recognized in Asset management, administration and distribution fees on the accompanying Consolidated Statements of Operations. Investment management fees from investment management agreements - Revenues based on assets of clients of the Institutional Investors segment primarily invested in Company-sponsored products. Each client is charged an investment management fee that is stated as a percentage of the market value of all assets under management. The client is billed directly on a quarterly basis. Revenues are recognized in Asset management, administration and distribution fees on the accompanying Consolidated Statements of Operations. Revenues associated with the separately managed account program offered through registered investment advisors located throughout the United States. The contractual fee is stated as a percentage of the market value of all assets invested in the separately managed account and collected on a quarterly basis. Revenues are recognized in Asset management, administration and distribution fees on the accompanying Consolidated Statements of Operations. Investment operations fees - Revenues earned from accounting and administrative services, distribution support services and regulatory and compliance services to investment management firms and family offices. The Company contracts directly with the investment management firm or family office. The contractual fees are stated as a percentage of net assets under administration and billed when asset valuations are finalized. Revenues are recognized in Asset management, administration and distribution fees on the accompanying Consolidated Statements of Operations. Investment processing fees - Platform as a Service - Revenues associated with clients that outsource their entire investment operation and back-office processing functions. Through the use of the Company's proprietary platforms, the Company assumes all back-office investment processing services including investment processing, custody and safekeeping of assets, income collections, securities settlement and other related trust activities. The contractual fee is based on either a monthly fee or a percentage of the value of assets processed on the Company's platforms each month as long as the fee is in excess of a monthly contractual minimum. The contractual fee may also include additional fees determined on a per-account or per-transaction basis. The client is billed directly on a monthly basis. Revenues are recognized in Information processing and software servicing fees on the accompanying Consolidated Statements of Operations. Investment processing fees - Software as a Service - Revenues associated with clients that outsource investment processing technology software and computer processing by accessing our proprietary software and data center remotely but retain responsibility for all investment operations, client administration and other back-office trust operations. The contractual fee is based on a monthly fee plus additional fees determined on a per-account or per-transaction basis. The client is billed directly on a monthly basis. Revenues are recognized in Information processing and software servicing fees on the accompanying Consolidated Statements of Operations. Professional services fees - Revenues associated with the business services migration for investment processing clients of the Private Banks segment and investment operations clients of the Investment Managers segment. In addition, Professional services include other services such as business transformation consulting. Typically, fees are stated as a contractual fixed fee. The client is billed directly and fees are collected according to the terms of the agreement. Account fees and other - Revenues associated with custody account servicing, account terminations, reimbursements received for out-of-pocket expenses, and other fees for the provision of ancillary services.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of PresentationThe accompanying Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States of America.
Variable Interest Entities	Variable Interest Entities The Company or its affiliates have 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. The Company receives asset management, distribution, administration and custodial fees for these services. Clients are the equity investors and participate in proportion to their ownership percentage in the net income or loss and net capital gains or losses of the products, and, on liquidation, will participate in proportion to their ownership percentage in the remaining net assets of the products after satisfaction of outstanding liabilities. The Company has concluded that it is not the primary beneficiary of the entities and, therefore, is not required to consolidate any of the pooled investment vehicles for which it receives asset management, distribution, administration and custodial fees under the VIE model.
Revenue Recognition	Revenue RecognitionRevenue is recognized when the transfer of control of promised goods or services under the terms of a contract with customers are satisfied in an amount that reflects the consideration to which the Company expects to be entitled in exchange for those promised goods or services. Certain portions of the Company’s revenues involve a third party in providing goods or services to its customers. In such circumstances, the Company must determine whether the nature of its promise to the customer is to provide the underlying goods or services (the Company is the principal in the transaction and reports the transaction gross) or to arrange for a third party to provide the underlying goods or services (the entity is the agent in the transaction and reports the transaction net).
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents includes $332,657 and $347,082 at September 30, 2021 and December 31, 2020, respectively, primarily invested in SEI-sponsored open-ended money market mutual funds. 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.
Restricted Cash	Restricted CashRestricted cash includes $250 and $3,000 at September 30, 2021 and December 31, 2020, respectively, segregated for regulatory purposes related to trade-execution services conducted by SEI Investments (Europe) Limited. Restricted cash also includes $101 at September 30, 2021 and December 31, 2020 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 (SEC) for broker-dealers.
Reclassifications	Reclassifications Certain prior year amounts have been reclassified to conform to current year presentation.
Equity Method Investments	The Company accounts for its interest in LSV using the equity method because of its less than 50% 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.
Fair Value of Financial Instruments	The fair value of the Company’s financial assets and liabilities, except for the Company's investment funds sponsored by LSV, is determined in accordance with the fair value hierarchy. The fair value of the Company’s Level 1 financial assets consist mainly of investments in open-ended mutual funds that are quoted daily. Level 2 financial assets consist of GNMA mortgage-backed securities held by the Company's wholly-owned limited purpose federal thrift subsidiary, SEI Private Trust Company (SPTC), Federal Home Loan Bank (FHLB) and other U.S. government agency short-term notes held by SIDCO. The financial assets held by SIDCO were purchased as part of a cash management program requiring only short term, top-tier investment grade government and corporate securities. The financial assets held by SPTC are debt securities issued by GNMA and are backed by the full faith and credit of the U.S. government. These securities were purchased for the sole purpose of satisfying applicable regulatory requirements and have maturity dates which range from 2023 to 2041. The fair value of the Company's investment funds sponsored by LSV is measured using the net asset value per share (NAV) as a practical expedient. The NAVs of the funds are calculated by the funds' independent custodian and are derived from the fair values of the underlying investments as of the reporting date. The funds allow for investor redemptions at the end of each calendar month. This investment has not been classified in the fair value hierarchy but is presented in the tables below to permit reconciliation to the amounts presented on the accompanying Consolidated Balance Sheets. The valuation of the Company's Level 2 financial assets held by SIDCO and SPTC are based upon securities pricing policies and procedures utilized by third-party pricing vendors.
Investments in Affiliated Funds	The fair value of the Company's investment funds sponsored by LSV is measured using the net asset value per share (NAV) as a practical expedient. The NAVs of the funds are calculated by the funds' independent custodian and are derived from the fair values of the underlying investments as of the reporting date. The funds allow for investor redemptions at the end of each calendar month. This investment has not been classified in the fair value hierarchy but is presented in the tables below to permit reconciliation to the amounts presented on the accompanying Consolidated Balance Sheets.
Available-for-sale Securities	These net unrealized gains are reported as a separate component of Accumulated other comprehensive loss on the accompanying Consolidated Balance Sheets.
Securities Owned	The Company’s broker-dealer subsidiary, SIDCO, has investments in U.S. government agency 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.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Calculation Of Basic And Diluted Earnings Per Share	The calculations of basic and diluted earnings per share for the three and nine months ended September 30, 2021 and 2020 are: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Net income $ 138,045 $ 111,096 $ 401,293 $ 321,404 Shares used to compute basic earnings per common share 140,507,000 145,812,000 141,928,000 147,586,000 Dilutive effect of stock options 1,919,000 2,095,000 2,053,000 2,372,000 Shares used to compute diluted earnings per common share 142,426,000 147,907,000 143,981,000 149,958,000 Basic earnings per common share $ 0.98 $ 0.76 $ 2.83 $ 2.18 Diluted earnings per common share $ 0.97 $ 0.75 $ 2.79 $ 2.14
Adjustments To Reconcile Net Income To Net Cash Provided By Operating Activities	The following table provides the details of the adjustments to reconcile net income to net cash provided by operating activities for the nine months ended September 30: 2021 2020 Net income $ 401,293 $ 321,404 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation 25,141 23,058 Amortization 43,749 39,417 Equity in earnings of unconsolidated affiliate (103,420) (86,488) Distributions received from unconsolidated affiliate 110,559 107,180 Stock-based compensation 31,173 20,458 Provision for losses on receivables 1,569 109 Deferred income tax expense (6,639) (7,731) Net (gain) loss from investments (134) 1,310 Change in other long-term liabilities 2,103 (4,442) Change in other assets 314 (965) Contract costs capitalized, net of amortization (482) (2,842) Other 921 (1,053) Change in current assets and liabilities (Increase) decrease in Receivables from investment products (4,537) 2,521 Receivables (58,537) (37,921) Other current assets (3,919) (6,186) Advances due from unconsolidated affiliate 51,422 12,641 (Decrease) increase in Accounts payable 3,006 8,615 Accrued liabilities (9,851) 8,809 Deferred revenue 150 (1,370) Total adjustments 82,588 75,120 Net cash provided by operating activities $ 483,881 $ 396,524

Investment In Unconsolidated _2

Investment In Unconsolidated Affiliate (Tables)	9 Months Ended
	Sep. 30, 2021
Equity Method Investments and Joint Ventures [Abstract]
Condensed Financial Information of LSV	These tables contain condensed financial information of LSV: Condensed Statement of Operations Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Revenues $ 115,728 $ 94,902 $ 342,957 $ 289,546 Net income 90,365 70,440 266,805 220,184 Condensed Balance Sheets September 30, 2021 December 31, 2020 Current assets $ 123,325 $ 151,515 Non-current assets 4,426 4,296 Total assets $ 127,751 $ 155,811 Current liabilities $ 69,349 $ 77,077 Non-current liabilities 4,058 4,620 Partners’ capital 54,344 74,114 Total liabilities and partners’ capital $ 127,751 $ 155,811

Composition of Certain Financ_2

Composition of Certain Financial Statement Captions (Tables)	9 Months Ended
	Sep. 30, 2021
Items Included in Consolidated Statement of Financial Condition [Abstract]
Schedule of Receivables	Receivables on the accompanying Consolidated Balance Sheets consist of: September 30, 2021 December 31, 2020 Trade receivables $ 112,572 $ 99,106 Fees earned, not billed 313,883 262,167 Other receivables 18,401 25,046 444,856 386,319 Less: Allowance for doubtful accounts (2,669) (1,100) $ 442,187 $ 385,219
Schedule of Property And Equipment	Property and Equipment on the accompanying Consolidated Balance Sheets consists of: September 30, 2021 December 31, 2020 Buildings $ 209,315 $ 206,151 Equipment 150,945 141,820 Land 24,651 24,179 Purchased software 156,327 147,838 Furniture and fixtures 21,196 21,439 Leasehold improvements 21,838 21,604 Construction in progress 209 4,660 584,481 567,691 Less: Accumulated depreciation (400,679) (378,639) Property and Equipment, net $ 183,802 $ 189,052
Schedule of Accrued Liabilities	Accrued liabilities on the accompanying Consolidated Balance Sheets consist of: September 30, 2021 December 31, 2020 Accrued employee compensation $ 86,924 $ 95,656 Accrued employee benefits and other personnel 11,743 18,770 Accrued consulting, outsourcing and professional fees 35,945 31,907 Accrued sub-advisory, distribution and other asset management fees 57,560 49,924 Accrued dividend payable — 53,127 Other accrued liabilities 38,871 50,461 Total accrued liabilities $ 231,043 $ 299,845

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Schedule of Fair Value Of Certain Financial Assets And Liabilities	The fair value of certain financial assets of the Company was determined using the following inputs: Fair Value Measurements at the End of the Reporting Period Using Assets September 30, 2021 Quoted Prices in Significant Equity securities $ 12,241 $ 12,241 $ — Available-for-sale debt securities 127,838 — 127,838 Fixed-income securities owned 31,770 — 31,770 Investment funds sponsored by LSV (1) 6,893 $ 178,742 $ 12,241 $ 159,608 Fair Value Measurements at the End of the Reporting Period Using Assets December 31, 2020 Quoted Prices in Significant Equity securities $ 12,142 $ 12,142 $ — Available-for-sale debt securities 93,277 — 93,277 Fixed-income securities owned 34,064 — 34,064 Investment funds sponsored by LSV (1) 6,166 $ 145,649 $ 12,142 $ 127,341

Marketable Securities (Tables)

Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2021
Marketable Securities [Abstract]
Schedule of Investments Available For Sale	Available For Sale and Equity Securities on the accompanying Consolidated Balance Sheets consist of: At September 30, 2021 Cost Gross Gross Fair Available-for-sale debt securities $ 126,964 $ 874 $ — $ 127,838 SEI-sponsored mutual funds 6,692 380 — 7,072 Equities and other mutual funds 4,932 237 — 5,169 $ 138,588 $ 1,491 $ — $ 140,079 At December 31, 2020 Cost Gross Gross Fair Available-for-sale debt securities $ 91,262 $ 2,015 $ — $ 93,277 SEI-sponsored mutual funds 6,866 382 — 7,248 Equities and other mutual funds 4,421 473 — 4,894 $ 102,549 $ 2,870 $ — $ 105,419

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2021
Stockholders' Equity Note [Abstract]
Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan	The Company recognized stock-based compensation expense in its Consolidated Financial Statements in the three and nine months ended September 30, 2021 and 2020, respectively, as follows: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Stock-based compensation expense $ 11,318 $ 6,467 $ 31,173 $ 20,458 Less: Deferred tax benefit (1,857) (1,229) (5,615) (3,932) Stock-based compensation expense, net of tax $ 9,461 $ 5,238 $ 25,558 $ 16,526

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	9 Months Ended
	Sep. 30, 2021
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule Of Accumulated Other Comprehensive Income (Loss), Net Of Tax	The components of Accumulated other comprehensive loss, net of tax, are as follows: Foreign Currency Translation Adjustments Unrealized Accumulated Other Comprehensive Loss Balance, January 1, 2021 $ (18,349) $ 1,551 $ (16,798) Other comprehensive loss before reclassifications (2,867) (1,548) (4,415) Amounts reclassified from accumulated other comprehensive loss — 670 670 Net current-period other comprehensive loss (2,867) (878) (3,745) Balance, September 30, 2021 $ (21,216) $ 673 $ (20,543)

Business Segment Information (T

Business Segment Information (Tables)	9 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Schedule Of Financial Information About Business Segments	The following tables highlight certain financial information about each of the business segments for the three months ended September 30, 2021 and 2020: Private Banks Investment Institutional Investment Investments Total For the Three Months Ended September 30, 2021 Revenues $ 123,018 $ 124,768 $ 85,759 $ 147,412 $ 4,365 $ 485,322 Expenses 116,679 62,107 41,643 89,594 12,820 322,843 Operating profit (loss) $ 6,339 $ 62,661 $ 44,116 $ 57,818 $ (8,455) $ 162,479 Private Investment Institutional Investment Investments Total For the Three Months Ended September 30, 2020 Revenues $ 114,792 $ 103,189 $ 79,583 $ 123,846 $ 3,517 $ 424,927 Expenses 113,066 51,519 37,812 79,838 13,315 295,550 Operating profit (loss) $ 1,726 $ 51,670 $ 41,771 $ 44,008 $ (9,798) $ 129,377 Private Investment Institutional Investment Investments Total For the Nine Months Ended September 30, 2021 Revenues $ 364,302 $ 357,458 $ 255,957 $ 426,639 $ 12,303 $ 1,416,659 Expenses 345,057 176,267 122,696 257,609 39,855 941,484 Operating profit (loss) $ 19,245 $ 181,191 $ 133,261 $ 169,030 $ (27,552) $ 475,175 Private Investment Institutional Investment Investments Total For the Nine Months Ended September 30, 2020 Revenues $ 335,739 $ 299,218 $ 235,309 $ 359,815 $ 10,254 $ 1,240,335 Expenses 331,442 154,100 113,016 228,795 37,691 865,044 Operating profit (loss) $ 4,297 $ 145,118 $ 122,293 $ 131,020 $ (27,437) $ 375,291
Reconciliation Of Total Operating Profit Reported For Business Segments To Income From Operations In Consolidated Statements Of Operations	A reconciliation of the total operating profit reported for the business segments to income from operations in the Consolidated Statements of Operations for the three months ended September 30, 2021 and 2020 is as follows: 2021 2020 Total operating profit from segments $ 162,479 $ 129,377 Corporate overhead expenses (21,354) (18,040) Income from operations $ 141,125 $ 111,337 A reconciliation of the total operating profit reported for the business segments to income from operations in the Consolidated Statements of Operations for the nine months ended September 30, 2021 and 2020: 2021 2020 Total operating profit from segments $ 475,175 $ 375,291 Corporate overhead expenses (65,192) (53,414) Income from operations $ 409,983 $ 321,877
Reconciliation of Other Significant Reconciling Items from Segments to Consolidated	The following tables provide additional information for the three months ended September 30, 2021 and 2020 pertaining to the business segments: Capital Expenditures (1) Depreciation 2021 2020 2021 2020 Private Banks $ 6,173 $ 7,652 $ 4,980 $ 4,222 Investment Advisors 2,896 3,234 499 1,255 Institutional Investors 720 698 271 298 Investment Managers 3,722 2,776 2,428 1,818 Investments in New Businesses 336 144 60 97 Total from business segments $ 13,847 $ 14,504 $ 8,238 $ 7,690 Corporate overhead 419 274 170 255 $ 14,266 $ 14,778 $ 8,408 $ 7,945 (1) Capital expenditures include additions to property and equipment and capitalized software. Amortization 2021 2020 Private Banks $ 8,526 $ 7,505 Investment Advisors 3,014 2,683 Institutional Investors 427 426 Investment Managers 2,451 2,343 Investments in New Businesses 185 186 Total from business segments $ 14,603 $ 13,143 Corporate overhead 71 57 $ 14,674 $ 13,200 The following tables provide additional information for the nine months ended September 30, 2021 and 2020: Capital Expenditures (1) Depreciation 2021 2020 2021 2020 Private Banks $ 20,596 $ 24,211 $ 13,290 $ 12,069 Investment Advisors 8,784 12,427 3,205 3,578 Institutional Investors 2,115 3,085 982 901 Investment Managers 8,726 19,067 6,508 5,499 Investments in New Businesses 788 894 306 243 Total from business segments $ 41,009 $ 59,684 $ 24,291 $ 22,290 Corporate Overhead 997 2,069 850 768 $ 42,006 $ 61,753 $ 25,141 $ 23,058 (1) Capital expenditures include additions to property and equipment and capitalized software. Amortization 2021 2020 Private Banks $ 25,735 $ 22,390 Investment Advisors 8,550 7,999 Institutional Investors 1,280 1,280 Investment Managers 7,375 7,020 Investments in New Businesses 555 556 Total from business segments $ 43,495 $ 39,245 Corporate Overhead 254 172 $ 43,749 $ 39,417

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Schedule Of Interest And Penalties	September 30, 2021 December 31, 2020 Gross liability for unrecognized tax benefits, exclusive of interest and penalties $ 16,721 $ 15,911 Interest and penalties on unrecognized benefits 1,835 2,105 Total gross uncertain tax positions $ 18,556 $ 18,016 Amount included in Current liabilities $ 4,497 $ 6,546 Amount included in Other long-term liabilities 14,059 11,470 $ 18,556 $ 18,016
Schedule of Effective Income Tax Rate Reconciliation	The effective income tax rate for the three and nine months ended September 30, 2021 and 2020 differs from the federal income tax statutory rate due to the following: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Statutory rate 21.0 % 21.0 % 21.0 % 21.0 % State taxes, net of federal tax benefit 2.5 3.3 3.0 3.2 Foreign tax expense and tax rate differential (0.1) (0.2) (0.1) (0.1) Tax benefit from stock option exercises (0.6) (0.4) (1.0) (1.0) Expiration of the statute of limitations — (1.3) — (0.5) State settlements (0.3) — (0.2) — Provision-to-return adjustment (0.5) (0.4) (0.2) (0.1) Other, net (0.3) (0.6) (0.3) (0.5) 21.7 % 21.4 % 22.2 % 22.0 %

Revenues from Contracts with _2

Revenues from Contracts with Customers (Tables)	9 Months Ended
	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following tables provide additional information pertaining to our revenues disaggregated by major product line and primary geographic market based on the location of the use of the products or services for each of the business segments for the three months ended September 30, 2021 and 2020: Private Banks Investment Institutional Investment Investments Total Major Product Lines: For the Three Months Ended September 30, 2021 Investment management fees from pooled investment products $ 34,212 $ 77,123 $ 13,639 $ 32 $ 338 $ 125,344 Investment management fees from investment management agreements 605 41,688 71,964 — 3,864 118,121 Investment operations fees 363 — — 136,978 — 137,341 Investment processing fees - PaaS 54,191 — — — — 54,191 Investment processing fees - SaaS 28,579 — — 3,848 — 32,427 Professional services fees 4,174 — — 871 — 5,045 Account fees and other 894 5,957 156 5,683 163 12,853 Total revenues $ 123,018 $ 124,768 $ 85,759 $ 147,412 $ 4,365 $ 485,322 Primary Geographic Markets: United States $ 77,260 $ 124,768 $ 68,810 $ 136,934 $ 4,365 $ 412,137 United Kingdom 28,767 — 13,327 — — 42,094 Canada 12,343 — 926 — — 13,269 Ireland 4,648 — 2,570 10,478 — 17,696 Other — — 126 — — 126 Total revenues $ 123,018 $ 124,768 $ 85,759 $ 147,412 $ 4,365 $ 485,322 Private Investment Institutional Investment Investments Total Major Product Lines: For the Three Months Ended September 30, 2020 Investment management fees from pooled investment products $ 32,256 $ 68,287 $ 13,417 $ 180 $ 356 $ 114,496 Investment management fees from investment management agreements 421 29,761 65,811 — 3,041 99,034 Investment operations fees 446 — — 113,037 — 113,483 Investment processing fees - PaaS 47,393 — — — — 47,393 Investment processing fees - SaaS 27,567 — — 3,479 — 31,046 Professional services fees 5,663 — — 2,016 — 7,679 Account fees and other 1,046 5,141 355 5,134 120 11,796 Total revenues $ 114,792 $ 103,189 $ 79,583 $ 123,846 $ 3,517 $ 424,927 Primary Geographic Markets: United States $ 74,633 $ 103,189 $ 62,699 $ 116,196 $ 3,517 $ 360,234 United Kingdom 25,234 — 12,930 — — 38,164 Canada 10,596 — 1,298 — — 11,894 Ireland 4,329 — 2,526 7,650 — 14,505 Other — — 130 — — 130 Total revenues $ 114,792 $ 103,189 $ 79,583 $ 123,846 $ 3,517 $ 424,927 The following tables provide additional information pertaining to our revenues disaggregated by major product line and primary geographic market based on the location of the use of the products or services for each of the Company’s business segments for the nine months ended September 30, 2021 and 2020: Private Investment Institutional Investment Investments Total Major Product Lines: For the Nine Months Ended September 30, 2021 Investment management fees from pooled investment products $ 100,484 $ 224,816 $ 41,365 $ 105 $ 993 $ 367,763 Investment management fees from investment management agreements 1,681 114,747 213,249 — 10,811 340,488 Investment operations fees 1,134 — — 394,401 — 395,535 Investment processing fees - PaaS 160,813 — — — — 160,813 Investment processing fees - SaaS 84,831 — — 11,409 — 96,240 Professional services fees 12,509 — — 2,885 — 15,394 Account fees and other 2,850 17,895 1,343 17,839 499 40,426 Total revenues $ 364,302 $ 357,458 $ 255,957 $ 426,639 $ 12,303 $ 1,416,659 Primary Geographic Markets: United States $ 231,203 $ 357,458 $ 203,322 $ 396,598 $ 12,303 $ 1,200,884 United Kingdom 83,514 — 41,091 — — 124,605 Canada 35,977 — 3,426 — — 39,403 Ireland 13,608 — 7,735 30,041 — 51,384 Other — — 383 — — 383 Total revenues $ 364,302 $ 357,458 $ 255,957 $ 426,639 $ 12,303 $ 1,416,659 Private Investment Institutional Investment Investments Total Major Product Lines: For the Nine Months Ended September 30, 2020 Investment management fees from pooled investment products $ 95,407 $ 200,718 $ 39,628 $ 536 $ 1,063 $ 337,352 Investment management fees from investment management agreements 1,060 83,726 194,445 — 8,912 288,143 Investment operations fees 1,359 — — 328,316 — 329,675 Investment processing fees - PaaS 137,737 — — — — 137,737 Investment processing fees - SaaS 84,783 — — 10,122 — 94,905 Professional services fees 11,535 — — 4,674 — 16,209 Account fees and other 3,858 14,774 1,236 16,167 279 36,314 Total revenues $ 335,739 $ 299,218 $ 235,309 $ 359,815 $ 10,254 $ 1,240,335 Primary Geographic Markets: United States $ 220,254 $ 299,218 $ 185,202 $ 335,776 $ 10,254 $ 1,050,704 United Kingdom 71,938 — 38,034 — — 109,972 Canada 30,723 — 4,327 — — 35,050 Ireland 12,824 — 7,321 24,039 — 44,184 Other — — 425 — — 425 Total revenues $ 335,739 $ 299,218 $ 235,309 $ 359,815 $ 10,254 $ 1,240,335

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Narrative) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Summary of Significant Accounting Policies [Line Items]
Cash and cash equivalents invested in SEI-sponsored money market funds	$ 793,883		$ 793,883		$ 784,626
Restricted cash	351		351		3,101
Capitalized software development costs			19,486	$ 18,640
Net book value of capitalized software	$ 250,280		$ 250,280		270,977
Anti-dilutive employee stock options (in shares)	11,347	8,813	11,531	8,342
Anti-dilutive employee stock options (in USD per share)	$ 57.80	$ 57.98	$ 57.78	$ 58.18
SEI Wealth Platform
Summary of Significant Accounting Policies [Line Items]
Capitalized software development costs			$ 19,387	$ 17,208
Net book value of capitalized software	$ 241,262		241,262
Capitalized software in progress	22,702		22,702		13,409
Amortization expense of capitalized software			$ 35,834	32,576
SEI Wealth Platform | Weighted Average
Summary of Significant Accounting Policies [Line Items]
Weighted average remaining life (in years)			10 years
SEI-Sponsored Open-Ended Money Market Mutual Funds
Summary of Significant Accounting Policies [Line Items]
Cash and cash equivalents invested in SEI-sponsored money market funds	332,657		$ 332,657		347,082
SEI Investments (Europe) Limited
Summary of Significant Accounting Policies [Line Items]
Restricted cash	250		250		3,000
SEI Investments Distribution Co. (SIDCO)
Summary of Significant Accounting Policies [Line Items]
Restricted cash	101		101		$ 101
SEI-Sponsored Open-Ended Money Market Mutual Funds
Summary of Significant Accounting Policies [Line Items]
Fees waived	$ 11,629	$ 8,575	$ 33,118	$ 24,930

Summary of Significant Accoun_5

Summary of Significant Accounting Policies (Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accounting Policies [Abstract]
Net income	$ 138,045	$ 111,096	$ 401,293	$ 321,404
Shares used to compute basic earnings per common share (in shares)	140,507	145,812	141,928	147,586
Dilutive effect of stock options (in shares)	1,919	2,095	2,053	2,372
Shares used to compute diluted earnings per common share (in shares)	142,426	147,907	143,981	149,958
Basic earnings per common share (in USD per share)	$ 0.98	$ 0.76	$ 2.83	$ 2.18
Diluted earnings per common share (in USD per share)	$ 0.97	$ 0.75	$ 2.79	$ 2.14

Summary of Significant Accoun_6

Summary of Significant Accounting Policies (Net Cash Provided by Operating Activities) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accounting Policies [Abstract]
Net income	$ 138,045	$ 111,096	$ 401,293	$ 321,404
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	8,408	7,945	25,141	23,058
Amortization	14,674	13,200	43,749	39,417
Equity in earnings of unconsolidated affiliate	(35,005)	(28,305)	(103,420)	(86,488)
Distributions received from unconsolidated affiliate			110,559	107,180
Stock-based compensation	11,318	6,467	31,173	20,458
Provision for losses on receivables			1,569	109
Deferred income tax expense			(6,639)	(7,731)
Net (gain) loss from investments	$ 575	$ (776)	(134)	1,310
Change in other long-term liabilities			2,103	(4,442)
Change in other assets			314	(965)
Contract costs capitalized, net of amortization			(482)	(2,842)
Other			921	(1,053)
Change in current assets and liabilities (Increase) decrease in
Receivables from investment products			(4,537)	2,521
Receivables			(58,537)	(37,921)
Other current assets			(3,919)	(6,186)
Advances due from unconsolidated affiliate			51,422	12,641
(Decrease) increase in
Accounts payable			3,006	8,615
Accrued liabilities			(9,851)	8,809
Deferred revenue			150	(1,370)
Total adjustments			82,588	75,120
Net cash provided by operating activities			$ 483,881	$ 396,524

Investment In Unconsolidated _3

Investment In Unconsolidated Affiliate (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Apr. 01, 2021	Mar. 31, 2021
Investments in and Advances to Affiliates [Line Items]
Distributions received from unconsolidated affiliate			$ 110,559	$ 107,180
Company's share in the earnings of equity method investee	$ 35,005	$ 28,305	103,420	86,488
LSV Asset Management
Investments in and Advances to Affiliates [Line Items]
Equity method investment, ownership percentage					38.70%	38.80%
Total investment in equity method investee	39,872		39,872
Distributions received from unconsolidated affiliate			110,559	107,180
Company's share in the earnings of equity method investee	$ 35,005	$ 28,305	$ 103,420	$ 86,488

Investment In Unconsolidated _4

Investment In Unconsolidated Affiliate (Statement of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Schedule of Equity Method Investments [Line Items]
Revenues	$ 485,322	$ 424,927	$ 1,416,659	$ 1,240,335
Equity Method Investment, Nonconsolidated Investee | LSV Asset Management
Schedule of Equity Method Investments [Line Items]
Revenues	115,728	94,902	342,957	289,546
Net income	$ 90,365	$ 70,440	$ 266,805	$ 220,184

Investment in Unconsolidated _5

Investment in Unconsolidated Affiliate (Balance Sheets) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Current assets	$ 1,370,614	$ 1,300,977
Total Assets	2,191,801	2,167,256
Current liabilities	253,462	317,275
Total Liabilities and Shareholders' Equity	2,191,801	2,167,256
Equity Method Investment, Nonconsolidated Investee | LSV Asset Management
Schedule of Equity Method Investments [Line Items]
Current assets	123,325	151,515
Non-current assets	4,426	4,296
Total Assets	127,751	155,811
Current liabilities	69,349	77,077
Non-current liabilities	4,058	4,620
Partners’ capital	54,344	74,114
Total Liabilities and Shareholders' Equity	$ 127,751	$ 155,811

Composition of Certain Financ_3

Composition of Certain Financial Statement Captions (Receivables) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Items Included in Consolidated Statement of Financial Condition [Abstract]
Trade receivables	$ 112,572	$ 99,106
Fees earned, not billed	313,883	262,167
Other receivables	18,401	25,046
Receivables, Gross, Current	444,856	386,319
Less: Allowance for doubtful accounts	(2,669)	(1,100)
Receivables, net	$ 442,187	$ 385,219

Composition of Certain Financ_4

Composition of Certain Financial Statement Captions (Property And Equipment) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Property and Equipment [Line Items]
Property and equipment, gross	$ 584,481		$ 584,481		$ 567,691
Less: Accumulated depreciation	(400,679)		(400,679)		(378,639)
Property and Equipment, net	183,802		183,802		189,052
Depreciation expense	8,408	$ 7,945	25,141	$ 23,058
Buildings
Property and Equipment [Line Items]
Property and equipment, gross	209,315		209,315		206,151
Equipment
Property and Equipment [Line Items]
Property and equipment, gross	150,945		150,945		141,820
Land
Property and Equipment [Line Items]
Property and equipment, gross	24,651		24,651		24,179
Purchased software
Property and Equipment [Line Items]
Property and equipment, gross	156,327		156,327		147,838
Furniture and fixtures
Property and Equipment [Line Items]
Property and equipment, gross	21,196		21,196		21,439
Leasehold improvements
Property and Equipment [Line Items]
Property and equipment, gross	21,838		21,838		21,604
Construction in progress
Property and Equipment [Line Items]
Property and equipment, gross	$ 209		$ 209		$ 4,660

Composition of Certain Financ_5

Composition of Certain Financial Statement Captions (Deferred Contract Costs) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Items Included in Consolidated Statement of Financial Condition [Abstract]
Deferred contract costs	$ 34,263,000		$ 34,263,000		$ 33,781,000
Capitalized contract cost, amount capitalized during period	$ 2,932,000	$ 2,521,000	6,978,000	$ 7,270,000
Amortization of deferred contract costs			6,496,000	$ 4,428,000
Capitalized contract cost impairment			$ 0

Composition of Certain Financ_6

Composition of Certain Financial Statement Captions (Accrued Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Items Included in Consolidated Statement of Financial Condition [Abstract]
Accrued employee compensation	$ 86,924	$ 95,656
Accrued employee benefits and other personnel	11,743	18,770
Accrued consulting, outsourcing and professional fees	35,945	31,907
Accrued sub-advisory, distribution and other asset management fees	57,560	49,924
Accrued dividend payable	0	53,127
Other accrued liabilities	38,871	50,461
Total accrued liabilities	$ 231,043	$ 299,845

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed-income securities owned	$ 31,770	$ 34,064
Assets, fair value	178,742	145,649
Quoted Prices in Active  Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed-income securities owned	0	0
Assets, fair value	12,241	12,142
Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed-income securities owned	31,770	34,064
Assets, fair value	159,608	127,341
Fair Value Measured at Net Asset Value Per Share
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment funds sponsored by LSV	6,893	6,166
Equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities	12,241	12,142
Equity securities | Quoted Prices in Active  Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities	12,241	12,142
Equity securities | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities	0	0
Available-for-sale debt securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities	127,838	93,277
Available-for-sale debt securities | Quoted Prices in Active  Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities	0	0
Available-for-sale debt securities | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities	$ 127,838	$ 93,277

Marketable Securities (Narrativ

Marketable Securities (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Schedule of Investments [Line Items]
Net unrealized gains (losses) of available-for-sale debt securities	$ 673,000		$ 673,000		$ 1,551,000
Unrealized gains (losses) during the period, income tax expense (benefit)	201,000		201,000		464,000
Available-for-sale securities, gross realized gains			0	$ 0
Mutual funds and equities, gross realized gains			714,000	254,000
Mutual funds and equities, gross realized loss			65,000	250,000
Other long-term investments	39,872,000		39,872,000		98,433,000
Securities owned	31,770,000		31,770,000		34,064,000
Cash Equivalents
Schedule of Investments [Line Items]
Cash equivalents at fair value	453,628,000		453,628,000		462,624,000
Available-for-sale debt securities
Schedule of Investments [Line Items]
Available-for-sale securities, gross realized losses			861,000	582,000
Investment Funds Sponsored by LSV
Schedule of Investments [Line Items]
Other long-term investments	6,893,000		6,893,000		$ 6,166,000
Unrealized gain (loss) on investments	$ (39,000)	$ 458,000	$ 727,000	$ (781,000)

Marketable Securities (Investme

Marketable Securities (Investments Available For Sale) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Available For Sale and Equity Securities, Cost	$ 138,588	$ 102,549
Available For Sale and Equity Securities, Gross Unrealized Gains	1,491	2,870
Available For Sale and Equity Securities, Gross Unrealized (Losses)	0	0
Available For Sale and Equity Securities, Fair Value	140,079	105,419
Available-for-sale debt securities
Debt Securities, Available-for-sale [Line Items]
Available for sale debt securities, Cost	126,964	91,262
Available for sale debt securities, Gross Unrealized Gains	874	2,015
Available for sale debt securities, Gross Unrealized (Losses)	0	0
Available for sale debt securities, Fair Value	127,838	93,277
SEI-sponsored mutual funds
Debt Securities, Available-for-sale [Line Items]
Equity securities, FV-NI, Cost	6,692	6,866
Equity securities, FV-NI, Gross Unrealized Gains	380	382
Equity securities, FV-NI, Gross Unrealized (Losses)	0	0
Equity securities, FV-NI, Fair Value	7,072	7,248
Equities and other mutual funds
Debt Securities, Available-for-sale [Line Items]
Equity securities, FV-NI, Cost	4,932	4,421
Equity securities, FV-NI, Gross Unrealized Gains	237	473
Equity securities, FV-NI, Gross Unrealized (Losses)	0	0
Equity securities, FV-NI, Fair Value	$ 5,169	$ 4,894

Line of Credit (Details)

Line of Credit (Details) - 2021 Credit Facility	Apr. 23, 2021USD ($)fiscalQuarter	Sep. 30, 2021USD ($)
Line of Credit Facility [Line Items]
Debt interest rate accrual term, number of preceding fiscal quarters | fiscalQuarter	4
Letters of credit outstanding amount		$ 5,808,000
Line of Credit
Line of Credit Facility [Line Items]
Credit facility term of agreement	5 years
Credit facility maximum borrowing capacity	$ 325,000,000
Credit facility stated percentage	0.00%
Credit facility accordion feature, increase limit	$ 100,000,000
Credit facility remaining borrowing capacity		$ 319,192,000
Line of Credit | London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Credit facility variable interest rate basis spread	1.00%
Line of Credit | Federal Funds Rate
Line of Credit Facility [Line Items]
Credit facility variable interest rate basis spread	0.50%
Line of Credit | Minimum
Line of Credit Facility [Line Items]
Credit facility commitment fee per annum on daily unused portion	0.15%
Line of Credit | Minimum | Lender's Base Rate Plus Market Spread
Line of Credit Facility [Line Items]
Credit facility variable interest rate basis spread	0.25%
Line of Credit | Minimum | London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Credit facility variable interest rate basis spread	1.25%
Line of Credit | Maximum
Line of Credit Facility [Line Items]
Credit facility commitment fee per annum on daily unused portion	0.30%
Line of Credit | Maximum | Lender's Base Rate Plus Market Spread
Line of Credit Facility [Line Items]
Credit facility variable interest rate basis spread	1.00%
Line of Credit | Maximum | London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Credit facility variable interest rate basis spread	2.00%
Letter of Credit
Line of Credit Facility [Line Items]
Credit facility maximum borrowing capacity	$ 15,000,000
Credit facility, commitment fee percentage	1.25%
Credit facility, fronting fee percentage	0.20%

Shareholders' Equity (Narrative

Shareholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	Jun. 02, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase (decrease) in stock-based compensation from change in management's estimate				$ 3,209	$ 0
Unrecognized compensation cost		$ 72,399		72,399
Total intrinsic value of options exercised				30,496
Aggregate intrinsic value of options exercisable		$ 104,146		$ 104,146
Market value of Company's common stock (in USD per share)		$ 59.30		$ 59.30
Weighted average exercise price per share (in USD per share)		$ 40.63		$ 40.63
Total options outstanding (in shares)		16,925		16,925
Total options exercisable (in shares)		5,578		5,578
Dividends declared per common share (in USD per share)	$ 0.37	$ 0	$ 0	$ 0.37	$ 0.35
Cash dividends declared				$ 52,389	$ 51,462
Common Stock Buyback
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares purchased and retired (in shares)				5,218
Company purchased, cost				$ 316,053
Remaining stock repurchase authorization amount		$ 126,775		$ 126,775
2014 Plan | Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rate				50.00%
2014 Plan | Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rate				50.00%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award waiting period				2 years
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award waiting period				4 years

Shareholders' Equity (Stock-Bas

Shareholders' Equity (Stock-Based Compensation Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Stockholders' Equity Note [Abstract]
Stock-based compensation expense	$ 11,318	$ 6,467	$ 31,173	$ 20,458
Less: Deferred tax benefit	(1,857)	(1,229)	(5,615)	(3,932)
Stock-based compensation expense, net of tax	$ 9,461	$ 5,238	$ 25,558	$ 16,526

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 1,805,606	$ 1,708,625	$ 1,739,907	$ 1,738,778
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Other comprehensive loss before reclassifications			(4,415)
Amounts reclassified from accumulated other comprehensive loss			670
Total other comprehensive (loss) income, net of tax	(6,021)	6,781	(3,745)	(3,894)
Ending balance	1,838,088	1,729,433	1,838,088	1,729,433
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			(18,349)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Other comprehensive loss before reclassifications			(2,867)
Amounts reclassified from accumulated other comprehensive loss			0
Total other comprehensive (loss) income, net of tax			(2,867)
Ending balance	(21,216)		(21,216)
Unrealized Gains (Losses) on Investments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			1,551
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Other comprehensive loss before reclassifications			(1,548)
Amounts reclassified from accumulated other comprehensive loss			670
Total other comprehensive (loss) income, net of tax			(878)
Ending balance	673		673
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(14,522)	(34,179)	(16,798)	(23,504)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Total other comprehensive (loss) income, net of tax	(6,021)	6,781	(3,745)	(3,894)
Ending balance	$ (20,543)	$ (27,398)	$ (20,543)	$ (27,398)

Business Segment Information (N

Business Segment Information (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Revenues	$ 485,322,000	$ 424,927,000	$ 1,416,659,000	$ 1,240,335,000
Intersegment
Segment Reporting Information [Line Items]
Revenues	$ 0	$ 0	$ 0	$ 0

Business Segment Information (S

Business Segment Information (Schedule of Financial Information About Business Segments) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Revenues	$ 485,322	$ 424,927	$ 1,416,659	$ 1,240,335
Expenses	322,843	295,550	941,484	865,044
Operating profit (loss)	162,479	129,377	475,175	375,291
Private Banks
Segment Reporting Information [Line Items]
Revenues	123,018	114,792	364,302	335,739
Expenses	116,679	113,066	345,057	331,442
Operating profit (loss)	6,339	1,726	19,245	4,297
Investment Advisors
Segment Reporting Information [Line Items]
Revenues	124,768	103,189	357,458	299,218
Expenses	62,107	51,519	176,267	154,100
Operating profit (loss)	62,661	51,670	181,191	145,118
Institutional Investors
Segment Reporting Information [Line Items]
Revenues	85,759	79,583	255,957	235,309
Expenses	41,643	37,812	122,696	113,016
Operating profit (loss)	44,116	41,771	133,261	122,293
Investment Managers
Segment Reporting Information [Line Items]
Revenues	147,412	123,846	426,639	359,815
Expenses	89,594	79,838	257,609	228,795
Operating profit (loss)	57,818	44,008	169,030	131,020
Investments In New Businesses
Segment Reporting Information [Line Items]
Revenues	4,365	3,517	12,303	10,254
Expenses	12,820	13,315	39,855	37,691
Operating profit (loss)	$ (8,455)	$ (9,798)	$ (27,552)	$ (27,437)

Business Segment Information (R

Business Segment Information (Reconciliation of Total Operating Profit) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Total operating profit from segments	$ 162,479	$ 129,377	$ 475,175	$ 375,291
Income from operations	141,125	111,337	409,983	321,877
Operating Segments
Segment Reporting Information [Line Items]
Total operating profit from segments	162,479	129,377	475,175	375,291
Corporate
Segment Reporting Information [Line Items]
Corporate overhead expenses	$ (21,354)	$ (18,040)	$ (65,192)	$ (53,414)

Business Segment Information _2

Business Segment Information (Schedule Of Additional Information Pertaining To Business Segments) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Capital Expenditures	$ 14,266	$ 14,778	$ 42,006	$ 61,753
Depreciation	8,408	7,945	25,141	23,058
Amortization	14,674	13,200	43,749	39,417
Operating Segments
Segment Reporting Information [Line Items]
Capital Expenditures	13,847	14,504	41,009	59,684
Depreciation	8,238	7,690	24,291	22,290
Amortization	14,603	13,143	43,495	39,245
Operating Segments | Private Banks
Segment Reporting Information [Line Items]
Capital Expenditures	6,173	7,652	20,596	24,211
Depreciation	4,980	4,222	13,290	12,069
Amortization	8,526	7,505	25,735	22,390
Operating Segments | Investment Advisors
Segment Reporting Information [Line Items]
Capital Expenditures	2,896	3,234	8,784	12,427
Depreciation	499	1,255	3,205	3,578
Amortization	3,014	2,683	8,550	7,999
Operating Segments | Institutional Investors
Segment Reporting Information [Line Items]
Capital Expenditures	720	698	2,115	3,085
Depreciation	271	298	982	901
Amortization	427	426	1,280	1,280
Operating Segments | Investment Managers
Segment Reporting Information [Line Items]
Capital Expenditures	3,722	2,776	8,726	19,067
Depreciation	2,428	1,818	6,508	5,499
Amortization	2,451	2,343	7,375	7,020
Operating Segments | Investments In New Businesses
Segment Reporting Information [Line Items]
Capital Expenditures	336	144	788	894
Depreciation	60	97	306	243
Amortization	185	186	555	556
Corporate
Segment Reporting Information [Line Items]
Capital Expenditures	419	274	997	2,069
Depreciation	170	255	850	768
Amortization	$ 71	$ 57	$ 254	$ 172

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Income Tax Contingency [Line Items]
Gross liability for unrecognized tax benefits, exclusive of interest and penalties	$ 16,721	$ 15,911
Unrecognized tax benefits that would affect effective tax rate	16,532	15,761
Interest and penalties on unrecognized benefits	1,835	$ 2,105
Settlement and Lapse of Statute
Income Tax Contingency [Line Items]
Unrecognized tax benefits within the next twelve months	$ 4,497

Income Taxes (Interest And Pena

Income Taxes (Interest And Penalties) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Gross liability for unrecognized tax benefits, exclusive of interest and penalties	$ 16,721	$ 15,911
Interest and penalties on unrecognized benefits	1,835	2,105
Total gross uncertain tax positions	18,556	18,016
Amount included in Current liabilities	4,497	6,546
Amount included in Other long-term liabilities	14,059	11,470
Total gross uncertain tax positions	$ 18,556	$ 18,016

Income Taxes (Effective Income

Income Taxes (Effective Income Tax Rate Reconciliation) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Statutory rate	21.00%	21.00%	21.00%	21.00%
State taxes, net of federal tax benefit	2.50%	3.30%	3.00%	3.20%
Foreign tax expense and tax rate differential	(0.10%)	(0.20%)	(0.10%)	(0.10%)
Tax benefit from stock option exercises	(0.60%)	(0.40%)	(1.00%)	(1.00%)
Expiration of the statute of limitations	0.00%	(1.30%)	0.00%	(0.50%)
State settlements	(0.30%)	0.00%	(0.20%)	0.00%
Provision-to-return adjustment	(0.50%)	(0.40%)	(0.20%)	(0.10%)
Other, net	(0.30%)	(0.60%)	(0.30%)	(0.50%)
Effective income tax rate	21.70%	21.40%	22.20%	22.00%

Commitments and Contingencies (

Commitments and Contingencies (Details)	Sep. 30, 2021lawsuit
Loss Contingencies [Line Items]
Number of lawsuits filed	7
Cases with SPTC as Defendant
Loss Contingencies [Line Items]
Number of lawsuits filed	4
Claims for Violations of Louisiana Racketeering Act
Loss Contingencies [Line Items]
Number of lawsuits filed	2
Cases Remaining in Parish of East Baton Rouge Granted Indefinite Extensions to Respond
Loss Contingencies [Line Items]
Number of lawsuits filed	2
Cases Filed in East Baton Rouge
Loss Contingencies [Line Items]
Number of lawsuits filed	2

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Details) - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Apr. 30, 2018	Jul. 31, 2017
Goodwill [Line Items]
Goodwill	$ 64,489,000		$ 64,489,000
Payment of contingent consideration	3,965,000	$ 633,000
Goodwill change during period	0
Amortization expense	2,763,000	2,763,000
Huntington Steele, LLC
Goodwill [Line Items]
Goodwill				$ 11,499,000
Payment of contingent consideration	3,965,000	$ 633,000
Contingent consideration, current	765,000
Contingent consideration, long-term	$ 8,099,000
Archway
Goodwill [Line Items]
Goodwill					$ 52,990,000

Revenues from Contracts with _3

Revenues from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Revenues	$ 485,322	$ 424,927	$ 1,416,659	$ 1,240,335
United States
Disaggregation of Revenue [Line Items]
Revenues	412,137	360,234	1,200,884	1,050,704
United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	42,094	38,164	124,605	109,972
Canada
Disaggregation of Revenue [Line Items]
Revenues	13,269	11,894	39,403	35,050
Ireland
Disaggregation of Revenue [Line Items]
Revenues	17,696	14,505	51,384	44,184
Other
Disaggregation of Revenue [Line Items]
Revenues	126	130	383	425
Investment management fees from pooled investment products
Disaggregation of Revenue [Line Items]
Revenues	125,344	114,496	367,763	337,352
Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	118,121	99,034	340,488	288,143
Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	137,341	113,483	395,535	329,675
Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	54,191	47,393	160,813	137,737
Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	32,427	31,046	96,240	94,905
Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	5,045	7,679	15,394	16,209
Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	12,853	11,796	40,426	36,314
Private Banks
Disaggregation of Revenue [Line Items]
Revenues	123,018	114,792	364,302	335,739
Private Banks | United States
Disaggregation of Revenue [Line Items]
Revenues	77,260	74,633	231,203	220,254
Private Banks | United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	28,767	25,234	83,514	71,938
Private Banks | Canada
Disaggregation of Revenue [Line Items]
Revenues	12,343	10,596	35,977	30,723
Private Banks | Ireland
Disaggregation of Revenue [Line Items]
Revenues	4,648	4,329	13,608	12,824
Private Banks | Other
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Private Banks | Investment management fees from pooled investment products
Disaggregation of Revenue [Line Items]
Revenues	34,212	32,256	100,484	95,407
Private Banks | Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	605	421	1,681	1,060
Private Banks | Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	363	446	1,134	1,359
Private Banks | Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	54,191	47,393	160,813	137,737
Private Banks | Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	28,579	27,567	84,831	84,783
Private Banks | Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	4,174	5,663	12,509	11,535
Private Banks | Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	894	1,046	2,850	3,858
Investment Advisors
Disaggregation of Revenue [Line Items]
Revenues	124,768	103,189	357,458	299,218
Investment Advisors | United States
Disaggregation of Revenue [Line Items]
Revenues	124,768	103,189	357,458	299,218
Investment Advisors | United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Advisors | Canada
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Advisors | Ireland
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Advisors | Other
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Advisors | Investment management fees from pooled investment products
Disaggregation of Revenue [Line Items]
Revenues	77,123	68,287	224,816	200,718
Investment Advisors | Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	41,688	29,761	114,747	83,726
Investment Advisors | Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Advisors | Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Advisors | Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Advisors | Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Advisors | Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	5,957	5,141	17,895	14,774
Institutional Investors
Disaggregation of Revenue [Line Items]
Revenues	85,759	79,583	255,957	235,309
Institutional Investors | United States
Disaggregation of Revenue [Line Items]
Revenues	68,810	62,699	203,322	185,202
Institutional Investors | United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	13,327	12,930	41,091	38,034
Institutional Investors | Canada
Disaggregation of Revenue [Line Items]
Revenues	926	1,298	3,426	4,327
Institutional Investors | Ireland
Disaggregation of Revenue [Line Items]
Revenues	2,570	2,526	7,735	7,321
Institutional Investors | Other
Disaggregation of Revenue [Line Items]
Revenues	126	130	383	425
Institutional Investors | Investment management fees from pooled investment products
Disaggregation of Revenue [Line Items]
Revenues	13,639	13,417	41,365	39,628
Institutional Investors | Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	71,964	65,811	213,249	194,445
Institutional Investors | Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Institutional Investors | Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Institutional Investors | Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Institutional Investors | Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Institutional Investors | Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	156	355	1,343	1,236
Investment Managers
Disaggregation of Revenue [Line Items]
Revenues	147,412	123,846	426,639	359,815
Investment Managers | United States
Disaggregation of Revenue [Line Items]
Revenues	136,934	116,196	396,598	335,776
Investment Managers | United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Managers | Canada
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Managers | Ireland
Disaggregation of Revenue [Line Items]
Revenues	10,478	7,650	30,041	24,039
Investment Managers | Other
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Managers | Investment management fees from pooled investment products
Disaggregation of Revenue [Line Items]
Revenues	32	180	105	536
Investment Managers | Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Managers | Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	136,978	113,037	394,401	328,316
Investment Managers | Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investment Managers | Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	3,848	3,479	11,409	10,122
Investment Managers | Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	871	2,016	2,885	4,674
Investment Managers | Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	5,683	5,134	17,839	16,167
Investments In New Businesses
Disaggregation of Revenue [Line Items]
Revenues	4,365	3,517	12,303	10,254
Investments In New Businesses | United States
Disaggregation of Revenue [Line Items]
Revenues	4,365	3,517	12,303	10,254
Investments In New Businesses | United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investments In New Businesses | Canada
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investments In New Businesses | Ireland
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investments In New Businesses | Other
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investments In New Businesses | Investment management fees from pooled investment products
Disaggregation of Revenue [Line Items]
Revenues	338	356	993	1,063
Investments In New Businesses | Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	3,864	3,041	10,811	8,912
Investments In New Businesses | Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investments In New Businesses | Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investments In New Businesses | Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investments In New Businesses | Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Investments In New Businesses | Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	$ 163	$ 120	$ 499	$ 279