SEI Investments (SEIC) 10-Q24 Oct 192019 Q3 Quarterly reportFinancial data

Company Profile

Cover

Cover - shares	9 Months Ended
Cover - shares	Sep. 30, 2019	Oct. 17, 2019
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Entity File Number	0-10200
Document Transition Report	false
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 Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		150,256,238
Entity Central Index Key	0000350894
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current Assets:
Cash and cash equivalents	$ 767,809	$ 754,525
Restricted cash	3,100	3,514
Receivables from investment products	52,140	49,869
Receivables, net of allowance for doubtful accounts of $1,311 and $718	349,332	315,336
Securities owned	32,862	30,892
Other current assets	34,894	36,676
Total Current Assets	1,240,137	1,190,812
Property and Equipment, net of accumulated depreciation of $346,377 and $338,206	154,584	145,863
Operating Lease Right-of-Use Assets	41,054
Capitalized Software, net of accumulated amortization of $430,644 and $395,171	300,848	309,500
Investments Available for Sale	101,580	111,901
Investments in Affiliated Funds, at fair value	5,533	4,887
Investment in Unconsolidated Affiliate	41,437	52,342
Goodwill	64,489	64,489
Intangible Assets, net of accumulated amortization of $7,853 and $5,090	28,907	31,670
Deferred Contract Costs	28,506	24,007
Deferred Income Taxes	1,421	2,042
Other Assets, net	32,109	34,155
Total Assets	2,040,605	1,971,668
Current Liabilities:
Accounts payable	8,712	10,920
Accrued liabilities	193,919	279,634
Current portion of long-term operating lease liabilities	7,888
Deferred revenue	5,529	5,154
Total Current Liabilities	216,048	295,708
Long-term Income Taxes Payable	803	803
Deferred Income Taxes	56,339	57,795
Long-term Operating Lease Liabilities	37,816
Other Long-term Liabilities	26,292	24,215
Total Liabilities	337,298	378,521
Commitments and Contingencies
Shareholders' Equity:
Common stock, $0.01 par value, 750,000 shares authorized; 150,222 and 153,634 shares issued and outstanding	1,502	1,536
Capital in excess of par value	1,137,636	1,106,641
Retained earnings	599,949	517,970
Accumulated other comprehensive loss, net	(35,780)	(33,000)
Total Shareholders' Equity	1,703,307	1,593,147
Total Liabilities and Shareholders' Equity	$ 2,040,605	$ 1,971,668

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current Assets:
Receivables, allowance for doubtful accounts	$ 1,311	$ 718
Property and Equipment, accumulated depreciation	346,377	338,206
Capitalized software, accumulated amortization	430,644	395,171
Intangible assets, accumulated amortization	$ 7,853	$ 5,090
Stockholders' 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	150,222,000	153,634,000
Common stock, shares outstanding	150,222,000	153,634,000

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Revenues	$ 416,254	$ 408,682	$ 1,226,660	$ 1,219,110
Expenses:
Subadvisory, distribution and other asset management costs	44,978	45,276	134,960	135,690
Software royalties and other information processing costs	7,198	7,767	22,719	24,462
Compensation, benefits and other personnel	130,579	127,480	386,913	379,132
Stock-based compensation	5,453	5,878	15,555	16,396
Consulting, outsourcing and professional fees	48,789	51,758	144,325	150,906
Data processing and computer related	22,338	21,754	65,514	63,478
Facilities, supplies and other costs	15,926	16,689	51,771	52,085
Amortization	12,947	12,405	38,407	36,420
Depreciation	7,409	7,255	22,162	21,515
Total expenses	295,617	296,262	882,326	880,084
Income from operations	120,637	112,420	344,334	339,026
Net gain (loss) from investments	611	89	2,121	(460)
Interest and dividend income	4,167	3,482	12,737	9,146
Interest expense	(154)	(122)	(477)	(511)
Equity in earnings of unconsolidated affiliate	37,609	41,726	112,758	123,406
Income before income taxes	162,870	157,595	471,473	470,607
Income taxes	30,702	29,276	98,784	80,773
Net income	$ 132,168	$ 128,319	$ 372,689	$ 389,834
Basic earnings per common share (in USD per share)	$ 0.88	$ 0.82	$ 2.45	$ 2.48
Shares used to compute basic earnings per share (in shares)	150,855	156,283	152,009	157,086
Diluted earnings per common share (in USD per share)	$ 0.86	$ 0.80	$ 2.40	$ 2.41
Shares used to compute diluted earnings per share (in shares)	154,227	160,511	155,311	162,053
Dividends declared per common share (in USD per share)	$ 0	$ 0	$ 0.33	$ 0.30
Asset management, administration and distribution fees
Revenues:
Revenues	$ 330,943	$ 322,778	$ 969,812	$ 955,495
Information processing and software servicing fees
Revenues:
Revenues	$ 85,311	$ 85,904	$ 256,848	$ 263,615

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 132,168	$ 128,319	$ 372,689	$ 389,834
Other comprehensive loss, net of tax:
Foreign currency translation adjustments	(5,207)	(435)	(4,687)	(7,261)
Unrealized gain (loss) on investments:
Unrealized gains (losses) during the period, net of income taxes of $(27), $91, $(497) and $463	71	(337)	1,633	(1,662)
Less: reclassification adjustment for losses (gains) realized in net income, net of income taxes of $(23), $(29), $(73) and $(75)	96	130	274	(32)
Unrealized gain (loss) on investments:	167	(207)	1,907	(1,694)
Total other comprehensive loss, net of tax	(5,040)	(642)	(2,780)	(8,955)
Comprehensive income	$ 127,128	$ 127,677	$ 369,909	$ 380,879

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Unrealized gains (losses) during the period, income tax expense (benefit)	$ (27)	$ 91	$ (497)	$ 463
Less: reclassification adjustment for losses realized in net income, income tax benefit	$ (23)	$ (29)	$ (73)	$ (75)

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, 2017		157,069
Beginning balance at Dec. 31, 2017	$ 1,476,839	$ 1,571	$ 1,027,709	$ 467,467	$ (19,908)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	389,834			389,834
Other comprehensive loss	(8,955)				(8,955)
Purchase and retirement of common stock	(289,534)	$ (44)	(21,507)	(267,983)
Purchase and retirement of common stock, shares		(4,419)
Issuance of common stock under employee stock purchase plan	3,258	$ 1	3,257
Issuance of common stock under the employee stock purchase plan, shares		57
Issuance of common stock upon exercise of stock options	75,409	$ 27	75,382
Issuance of common stock upon exercise of stock options, shares		2,768
Stock-based compensation	16,396		16,396
Dividends declared	(47,139)			(47,139)
Ending balance at Sep. 30, 2018	1,630,510	$ 1,555	1,101,237	556,581	(28,863)
Ending balance, shares at Sep. 30, 2018		155,475
Beginning balance, shares at Jun. 30, 2018		156,800
Beginning balance at Jun. 30, 2018	1,590,882	$ 1,568	1,094,771	522,764	(28,221)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	128,319			128,319
Other comprehensive loss	(642)				(642)
Purchase and retirement of common stock	(102,636)	$ (17)	(8,117)	(94,502)
Purchase and retirement of common stock, shares		(1,668)
Issuance of common stock under employee stock purchase plan	1,107	$ 1	1,106
Issuance of common stock under the employee stock purchase plan, shares		21
Issuance of common stock upon exercise of stock options	7,602	$ 3	7,599
Issuance of common stock upon exercise of stock options, shares		322
Stock-based compensation	5,878		5,878
Ending balance at Sep. 30, 2018	$ 1,630,510	$ 1,555	1,101,237	556,581	(28,863)
Ending balance, shares at Sep. 30, 2018		155,475
Beginning balance, shares at Dec. 31, 2018	153,634	153,634
Beginning balance at Dec. 31, 2018	$ 1,593,147	$ 1,536	1,106,641	517,970	(33,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	372,689			372,689
Other comprehensive loss	(2,780)				(2,780)
Purchase and retirement of common stock	(267,184)	$ (50)	(26,408)	(240,726)
Purchase and retirement of common stock, shares		(4,950)
Issuance of common stock under employee stock purchase plan	3,392	$ 1	3,391
Issuance of common stock under the employee stock purchase plan, shares		77
Issuance of common stock upon exercise of stock options	38,472	$ 15	38,457
Issuance of common stock upon exercise of stock options, shares		1,461
Stock-based compensation	15,555		15,555
Dividends declared	(49,984)			(49,984)
Ending balance at Sep. 30, 2019	$ 1,703,307	$ 1,502	1,137,636	599,949	(35,780)
Ending balance, shares at Sep. 30, 2019	150,222	150,222
Beginning balance, shares at Jun. 30, 2019		150,955
Beginning balance at Jun. 30, 2019	$ 1,634,501	$ 1,509	1,122,068	541,664	(30,740)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	132,168			132,168
Other comprehensive loss	(5,040)				(5,040)
Purchase and retirement of common stock	(81,367)	$ (15)	(7,469)	(73,883)
Purchase and retirement of common stock, shares		(1,400)
Issuance of common stock under employee stock purchase plan	999	$ 1	998
Issuance of common stock under the employee stock purchase plan, shares		21
Issuance of common stock upon exercise of stock options	16,593	$ 7	16,586
Issuance of common stock upon exercise of stock options, shares		646
Stock-based compensation	5,453		5,453
Ending balance at Sep. 30, 2019	$ 1,703,307	$ 1,502	$ 1,137,636	$ 599,949	$ (35,780)
Ending balance, shares at Sep. 30, 2019	150,222	150,222

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Equity (Unaudited) (Parenthetical) - $ / shares	May 29, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Stockholders' Equity [Abstract]
Dividends declared per common share (in USD per share)	$ 0.33	$ 0	$ 0	$ 0.33	$ 0.30

Consolidated Condensed Statemen

Consolidated Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net income	$ 372,689	$ 389,834
Adjustments to reconcile net income to net cash provided by operating activities (See Note 1)	8,846	28,064
Net cash provided by operating activities	381,535	417,898
Cash flows from investing activities:
Additions to property and equipment	(30,515)	(21,652)
Additions to capitalized software	(26,821)	(33,371)
Purchases of marketable securities	(126,030)	(122,259)
Prepayments and maturities of marketable securities	137,783	116,568
Cash paid for acquisition, net of cash acquired	0	(5,794)
Other investing activities	2,538	(10,900)
Net cash used in investing activities	(43,045)	(77,408)
Cash flows from financing activities:
Repayments under revolving credit facility	0	(30,000)
Purchase and retirement of common stock	(262,861)	(290,563)
Proceeds from issuance of common stock	41,864	78,667
Payment of dividends	(100,745)	(94,318)
Net cash used in financing activities	(321,742)	(336,214)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(3,878)	(6,552)
Net increase (decrease) in cash, cash equivalents and restricted cash	12,870	(2,276)
Cash, cash equivalents and restricted cash, beginning of period	758,039	747,752
Cash, cash equivalents and restricted cash, end of period	770,909	745,476
Non-cash operating activities:
Operating lease right-of-use assets and lease liabilities recorded upon adoption of ASC 842	$ 44,169	$ 0

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
Summary of Significant Accounting Policies	Sep. 30, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Nature of Operations SEI Investments Company (the Company), a Pennsylvania corporation, provides investment processing, investment management, and investment operations platforms to financial institutions, financial advisors, institutional investors, investment managers and ultra-high-net-worth families in the United States, Canada, the United Kingdom, continental Europe and various other locations throughout the world. Investment processing platforms consist of application and business process outsourcing services, professional services and transaction-based services. Revenues from investment processing platforms are recognized in Information processing and software servicing fees on the accompanying Consolidated Statements of Operations. Investment management programs consist of mutual funds, alternative investments and separate accounts. These include a series of money market, equity, fixed-income and alternative investment portfolios, primarily in the form of registered investment companies. The Company serves as the administrator and investment advisor for many of these products. Revenues from investment management programs are recognized in Asset management, administration and distribution fees on the accompanying Consolidated Statements of Operations. Investment operations platforms consist of outsourcing services including fund and investment accounting, administration, reconciliation, investor servicing and client reporting. Revenues from investment operations 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, 2019 , the results of operations for the three and nine months ended September 30, 2019 and 2018 , and cash flows for the nine -month periods ended September 30, 2019 and 2018 . 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, 2018 . The Company adopted the requirements of the Accounting Standards Update (ASU) No. 2016-2 Leases (Topic 842) (Accounting Standards Codifications (ASC) 842 (ASC 842)) using the modified retrospective method during the nine months ended September 30, 2019 . As a result of the adoption of ASC 842, the Company recorded additional lease assets and net lease liabilities of $44,169 as of January 1, 2019. Upon implementation, the Company elected the package of practical expedients permitted under the transition guidance within the new standard which allowed the Company to carryforward the historical lease identification, classification and initial direct cost. ASC 842 did not materially impact the Company’s consolidated net income or consolidated cash flows (see following caption "Leases"). With the exception of the adoption of ASC 842, there have been no significant changes in significant accounting policies during the nine months ended September 30, 2019 as compared to the significant accounting policies described in the Company's Annual Report on Form 10-K for the year ended December 31, 2018 . 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 entities either do not meet the definition of a VIE or the Company does not hold a variable interest in the entities. The entities either qualify for the money market scope exception, or are entities in which the Company’s asset management, distribution, administration and custodial fees are commensurate with the services provided and include fair terms and conditions, or are entities that are limited partnerships which have substantive kick-out rights. The Company acts as a fiduciary and does not hold any other interests other than insignificant seed money investments in the pooled investment vehicles. For this reason, the Company also concluded that it is not required to consolidate the pooled investment vehicles under the voting interest entity 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 $6,390 and $6,525 in fees during the three months ended September 30, 2019 and 2018 , respectively. During the nine months ended September 30, 2019 and 2018 , the Company waived $21,091 and $19,551 , 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). Cash and Cash Equivalents Cash and cash equivalents includes $319,977 and $315,840 at September 30, 2019 and December 31, 2018 , respectively, primarily invested in SEI-sponsored open-ended money market mutual funds. The SEI-sponsored mutual funds are Level 1 assets. Restricted Cash Restricted cash includes $3,000 at September 30, 2019 and December 31, 2018 segregated for regulatory purposes related to trade-execution services conducted by SEI Investments (Europe) Limited. Restricted cash also includes $100 and $514 at September 30, 2019 and December 31, 2018 , respectively, 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 $26,821 and $33,371 of software development costs during the nine months ended September 30, 2019 and 2018 , respectively. The Company's software development costs primarily relate to significant enhancements to the SEI Wealth Platform SM (SWP). The Company capitalized $26,029 and $32,526 of software development costs for significant enhancements to SWP during the nine months ended September 30, 2019 and 2018 , respectively. As of September 30, 2019 , the net book value of SWP was $283,128 . The net book value includes $51,781 of capitalized software development costs in-progress associated with future releases. Capitalized software development costs in-progress associated with future releases of SWP were $42,238 as of December 31, 2018 . SWP has a weighted average remaining life of 8.4 years . Amortization expense for SWP was $31,567 and $29,723 during the nine months ended September 30, 2019 and 2018 , respectively. Earnings per Share The calculations of basic and diluted earnings per share for the three and nine months ended September 30, 2019 and 2018 are: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Net income $ 132,168 $ 128,319 $ 372,689 $ 389,834 Shares used to compute basic earnings per common share 150,855,000 156,283,000 152,009,000 157,086,000 Dilutive effect of stock options 3,372,000 4,228,000 3,302,000 4,967,000 Shares used to compute diluted earnings per common share 154,227,000 160,511,000 155,311,000 162,053,000 Basic earnings per common share $ 0.88 $ 0.82 $ 2.45 $ 2.48 Diluted earnings per common share $ 0.86 $ 0.80 $ 2.40 $ 2.41 During the three months ended September 30 , 2019 and 2018 , employee stock options to purchase 6,239,000 and 6,183,000 shares of common stock with an average exercise price of $54.91 and $53.38 , respectively, were outstanding but not included in the computation of diluted earnings per common share. During the nine months ended September 30, 2019 and 2018 , employee stock options to purchase 6,269,000 and 6,153,000 shares of common stock with an average exercise price of $54.84 and $53.15 , 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. Leases The Company determines if an arrangement is a lease at the inception of the contract. The Company's operating leases are included in Operating lease right-of-use (ROU) assets, Current portion of long-term operating lease liabilities, and Long-term operating lease liabilities on the accompanying Consolidated Balance Sheet. The operating lease ROU assets and operating lease liabilities are recognized based on the present value of future minimum lease payments over the lease term at commencement date. As most of the Company’s leases do not provide an implicit interest rate, the Company utilizes an estimated incremental borrowing rate based on the information available at commencement date in determining the present value of future payments. In determining the discount rate used in the present value calculation, the Company has elected to apply the portfolio approach for leases of equipment provided the leases commenced at or around the same time. This election allows the Company to account for leases at a portfolio level provided that the resulting accounting at this level would not differ materially from the accounting at the individual lease level. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. The Company has elected to account for lease and non-lease components separately. Operating lease ROU assets include all contractual lease payments and initial direct costs incurred, less any lease incentives. Facility leases generally only contain lease expense and non-component items such as taxes and pass through charges. Only the lease components are included in the ROU assets and lease liabilities. Additionally, the Company has elected not to apply the recognition requirements of ASC 842 to leases which have a lease term of less than one year at the commencement date. The majority of the Company's leases for corporate facilities and equipment contain terms for renewal and extension of the lease agreement. The exercise of lease renewal options is generally at the Company’s sole discretion. The Company includes the lease extensions when it is reasonably certain the Company will exercise the extension. The Company’s lease agreements do not contain any material variable lease payments, material residual value guarantees or any material restrictive covenants. The Company does not currently have any finance leases. See Note 15 for information on related disclosures regarding leases. New Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13) and a subsequent amendment ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments (ASU 2019-04) in April 2019. ASU 2016-13 requires that expected credit losses relating to financial assets measured on an amortized cost basis and available-for-sale debt securities be recorded through an allowance for credit losses. ASU 2016-13 limits the amount of credit losses to be recognized for available-for-sale debt securities to the amount by which carrying value exceeds fair value and also requires the reversal of previously recognized credit losses if fair value increases. ASU 2019-04 provides certain improvements to ASU 2016-13. ASU 2016-13 and ASU 2019-04 become effective for the Company during the first quarter of 2020. Early adoption is permitted. The Company is currently finalizing its evaluation of ASU 2016-13 and ASU 2019-04 and does not believe the adoption of the updated standards will have a material impact on its consolidated financial statements and related disclosures. In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment (ASU 2017-04). The objective of ASU 2017-04 is to simplify the subsequent measurement of goodwill by entities performing their annual goodwill impairment tests by comparing the fair value of a reporting unit, including income tax effects from any tax-deductible goodwill, with its carrying amount and recognizing an impairment charge for the amount by which the carrying amount exceeds fair value. ASU 2017-04 is effective for the Company beginning in the first quarter of 2020. Early adoption is permitted. The Company does not believe the adoption of ASU 2017-04 will have a material impact on its consolidated financial statements and related disclosures. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement (ASU 2018-13) which modifies the disclosure requirements on fair value measurements. ASU 2018-13 is effective for the Company beginning in the first quarter of 2020. The Company is currently finalizing its evaluation of ASU 2018-13 and does not believe the adoption of the updated standard will have a material impact on its consolidated financial statements and related disclosures. In October 2018, the FASB issued ASU 2018-17, Consolidation (Topic 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities (ASU 2018-17). The new standard changes how entities evaluate decision-making fees under the variable interest entity guidance. ASU 2018-17 is effective for the Company beginning in the first quarter of 2020. The Company does not believe the adoption of ASU 2018-17 will have a material impact on its consolidated financial statements and related disclosures. 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 : 2019 2018 Net income $ 372,689 $ 389,834 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation 22,162 21,515 Amortization 38,407 36,420 Equity in earnings of unconsolidated affiliate (112,758 ) (123,406 ) Distributions received from unconsolidated affiliate 123,663 138,216 Stock-based compensation 15,555 16,396 Provision for losses on receivables 593 (29 ) Deferred income tax expense (1,405 ) 8,378 Net (gain) loss from investments (2,121 ) 460 Change in long-term income taxes payable — (9,859 ) Change in other long-term liabilities 2,077 1,930 Change in other assets (56 ) (4,214 ) Contract costs capitalized, net of amortization (4,499 ) (3,463 ) Other (721 ) (99 ) Change in current assets and liabilities (Increase) decrease in Receivables from investment products (2,271 ) 2,263 Receivables (34,589 ) (44,878 ) Other current assets 729 (5,955 ) (Decrease) increase in Accounts payable (2,208 ) 3,893 Accrued liabilities (34,087 ) (9,717 ) Deferred revenue 375 213 Total adjustments 8,846 28,064 Net cash provided by operating activities $ 381,535 $ 417,898

Investment In Unconsolidated Af

Investment In Unconsolidated Affiliate	9 Months Ended
Investment In Unconsolidated Affiliate	Sep. 30, 2019
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, 2019 was 38.9% . 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, 2019 , the Company’s total investment in LSV was $41,437 . The Company receives partnership distributions from LSV on a quarterly basis. The Company received partnership distributions from LSV of $123,663 and $138,216 in the nine months ended September 30 , 2019 and 2018 , 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 $37,609 and $41,726 during the three months ended September 30 , 2019 and 2018 , respectively. During the nine months ended September 30, 2019 and 2018 , the Company’s proportionate share in the earnings of LSV was $112,758 and $123,406 , respectively. These tables contain condensed financial information of LSV: Condensed Statement of Operations Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Revenues $ 121,232 $ 133,921 $ 365,164 $ 397,750 Net income 96,699 107,284 289,918 317,295 Condensed Balance Sheets September 30, 2019 December 31, 2018 Current assets $ 138,320 $ 138,083 Non-current assets 4,721 1,165 Total assets $ 143,041 $ 139,248 Current liabilities $ 75,192 $ 47,874 Non-current liabilities 4,738 — Partners’ capital 63,111 91,374 Total liabilities and partners’ capital $ 143,041 $ 139,248

Composition of Certain Financia

Composition of Certain Financial Statement Captions	9 Months Ended
Composition of Certain Financial Statement Captions	Sep. 30, 2019
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, 2019 December 31, 2018 Trade receivables $ 91,372 $ 76,362 Fees earned, not billed 241,340 226,001 Other receivables 17,931 13,691 350,643 316,054 Less: Allowance for doubtful accounts (1,311 ) (718 ) $ 349,332 $ 315,336 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, 2019 December 31, 2018 Buildings $ 162,677 $ 160,796 Equipment 119,585 126,954 Land 10,830 10,772 Purchased software 142,693 139,245 Furniture and fixtures 18,478 18,103 Leasehold improvements 19,656 18,959 Construction in progress 27,042 9,240 500,961 484,069 Less: Accumulated depreciation (346,377 ) (338,206 ) Property and Equipment, net $ 154,584 $ 145,863 The Company recognized $22,162 and $21,515 in depreciation expense related to property and equipment for the nine months ended September 30 , 2019 and 2018 , respectively. Deferred Contract Costs Deferred contract costs, which primarily consist of deferred sales commissions, were $28,506 and $24,007 as of September 30, 2019 and December 31, 2018 , respectively. The Company deferred expenses related to contract costs of $4,575 and $1,400 during the three months ended September 30, 2019 and 2018 , respectively. During the nine months ended September 30, 2019 and 2018 , the Company deferred expenses related to contract costs of $7,673 and $5,483 , respectively. Amortization expense related to deferred contract costs were $3,174 and $2,020 during the nine months ended September 30, 2019 and 2018 , 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, 2019 . Accrued Liabilities Accrued liabilities on the accompanying Consolidated Balance Sheets consist of: September 30, 2019 December 31, 2018 Accrued employee compensation $ 73,997 $ 97,603 Accrued consulting, outsourcing and professional fees 27,491 31,000 Accrued sub-advisory, distribution and other asset management fees 45,495 42,583 Accrued dividend payable — 50,761 Other accrued liabilities 46,936 57,687 Total accrued liabilities $ 193,919 $ 279,634

Fair Value Measurements

Fair Value Measurements	9 Months Ended
Fair Value Measurements	Sep. 30, 2019
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 Government National Mortgage Association (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 , 2019 were consistent with those as described in our Annual Report on Form 10-K at December 31, 2018 . The Company had no Level 3 financial assets at September 30, 2019 or December 31, 2018 that were required to be measured at fair value on a recurring basis. The Company's Level 3 financial liabilities at September 30, 2019 and December 31, 2018 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 correlation coefficient. There were no transfers of financial assets between levels within the fair value hierarchy during the nine months ended September 30 , 2019 . 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, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Equity available-for-sale securities $ 11,313 $ 11,313 $ — Fixed-income available-for-sale securities 90,267 — 90,267 Fixed-income securities owned 32,862 — 32,862 Investment funds sponsored by LSV (1) 5,533 $ 139,975 $ 11,313 $ 123,129 Fair Value Measurements at the End of the Reporting Period Using Assets December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Equity available-for-sale securities $ 10,218 $ 10,218 $ — Fixed-income available-for-sale securities 101,683 — 101,683 Fixed-income securities owned 30,892 — 30,892 Investment funds sponsored by LSV (1) 4,887 $ 147,680 $ 10,218 $ 132,575 (1) The fair value amounts presented in the tables above are intended to permit reconciliation of the fair value hierarchy to the amounts presented on the accompanying Consolidated Balance Sheets (See Note 5

Marketable Securities

Marketable Securities	9 Months Ended
Marketable Securities	Sep. 30, 2019
Marketable Securities [Abstract]
Marketable Securities	Marketable Securities Investments Available for Sale Investments available for sale classified as non-current assets consist of: At September 30, 2019 Cost Amount Gross Unrealized Gains Gross Unrealized (Losses) Fair Value SEI-sponsored mutual funds $ 7,477 $ 105 $ (411 ) $ 7,171 Equities and other mutual funds 3,476 666 — 4,142 Debt securities 89,625 642 — 90,267 $ 100,578 $ 1,413 $ (411 ) $ 101,580 At December 31, 2018 Cost Amount Gross Unrealized Gains Gross Unrealized (Losses) Fair Value SEI-sponsored mutual funds $ 7,446 $ — $ (788 ) $ 6,658 Equities and other mutual funds 3,434 126 — 3,560 Debt securities 103,518 — (1,835 ) 101,683 $ 114,398 $ 126 $ (2,623 ) $ 111,901 Net unrealized gains at September 30, 2019 of the Company's available-for-sale debt securities were $494 (net of income tax expense of $148 ). Net unrealized losses at December 31, 2018 of the Company's available-for-sale debt securities were $1,413 (net of income tax benefit of $422 ). These net unrealized gains and losses are reported as a separate component of Accumulated other comprehensive loss on the accompanying Consolidated Balance Sheets. There were gross realized gains of $1,031 and gross realized losses of $1,520 during the nine months ended September 30 , 2018 . Gross realized gains and losses from available-for-sale securities during the nine months ended September 30 , 2019 were immaterial. Gains and losses from available-for-sale securities, including amounts reclassified from accumulated comprehensive loss, are reflected in Net gain (loss) 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 gain (loss) from investments on the accompanying Consolidated Statements of Operations. The investment primarily consists of U.S. dollar denominated funds that invest primarily in securities of Canadian, Australian and Japanese companies as well as various other global securities. The underlying securities held by the funds are translated into U.S. dollars within the funds. The funds had a fair value of $5,533 and $4,887 at September 30, 2019 and December 31, 2018 , respectively. The Company recognized gains of $646 and losses of $298 during the nine months ended September 30, 2019 and 2018 , respectively, from the change in fair value of the funds. There were no material gains or losses during the three months ended September 30, 2019 and 2018 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 $32,862 and $30,892 at September 30, 2019 and December 31, 2018 , respectively. There were no material net gains or losses related to the securities during the three and nine months ended September 30, 2019 and 2018 .

Line of Credit

Line of Credit	9 Months Ended
Line of Credit	Sep. 30, 2019
Line of Credit Facility [Abstract]
Line of Credit	Line of Credit The Company has a five-year $300,000 Credit Agreement (the Credit Facility) with Wells Fargo Bank, National Association, and a syndicate of other lenders. The Credit Facility is scheduled to expire in June 2021, 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 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 a fronting fee of 0.175% of the aggregate face amount of the outstanding letters of credit issued under the Credit Facility. The Credit Facility contains covenants that restrict the ability of the Company to engage in mergers, consolidations, asset sales, investments, transactions with affiliates other than wholly-owned subsidiaries, or to incur liens or other indebtedness including contingent obligations or guarantees, 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, 2019 , the Company had outstanding letters of credit of $11,553 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 the remainder of 2019. The amount of the Credit Facility that is available for general corporate purposes as of September 30, 2019 was $288,447 . The Company was in compliance with all covenants of the Credit Facility during the nine months ended September 30, 2019

Shareholders' Equity

Shareholders' Equity	9 Months Ended
Shareholders' Equity	Sep. 30, 2019
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 diluted earnings per share target is achieved, and the remaining 50% when a second, higher specified diluted earnings per share target is achieved. Options do not vest due to the passage of time but solely 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 or four year waiting period from the grant date along with the attainment of the applicable financial vesting target. Earnings per share targets exclude the impact of stock-based compensation and are established at time of grant. The targets are measured annually on December 31. The amount of stock-based compensation expense recognized in the period is based upon management’s estimate of when the earnings per share 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, 2019 and 2018 , respectively, as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Stock-based compensation expense $ 5,453 $ 5,878 $ 15,555 $ 16,396 Less: Deferred tax benefit (1,042 ) (1,311 ) (2,959 ) (3,556 ) Stock-based compensation expense, net of tax $ 4,411 $ 4,567 $ 12,596 $ 12,840 As of September 30, 2019 , there was approximately $50,330 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 , 2019 was $43,246 . The total options exercisable as of September 30, 2019 had an intrinsic value of $197,860 . 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, 2019 and the weighted average exercise price of the options. The market value of the Company’s common stock as of September 30, 2019 was $59.26 as reported by the Nasdaq Stock Market, LLC. The weighted average exercise price of the options exercisable as of September 30, 2019 was $25.08 . Total options that were outstanding as of September 30, 2019 were 14,132,000 . Total options that were exercisable as of September 30, 2019 were 7,890,000 . Common Stock Buyback The Company’s Board of Directors, under multiple authorizations, has authorized the repurchase of the Company’s common stock on the open market or through private transactions. The Company purchased 4,950,000 shares at a total cost of $267,184 during the nine months ended September 30 , 2019 , 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, 2019 , the Company had approximately $198,695 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 May 29, 2019 , the Board of Directors declared a cash dividend of $0.33 per share on the Company's common stock, which was paid on June 20, 2019 , to shareholders of record on June 12, 2019 . Cash dividends declared during the nine months ended September 30, 2019 and 2018 were $49,984 and $47,139

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	9 Months Ended
Accumulated Other Comprehensive Loss	Sep. 30, 2019
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 Gains (Losses) on Investments Accumulated Other Comprehensive Loss Balance, January 1, 2019 $ (31,587 ) $ (1,413 ) $ (33,000 ) Other comprehensive loss before reclassifications (4,687 ) 1,633 (3,054 ) Amounts reclassified from accumulated other comprehensive loss — 274 274 Net current-period other comprehensive loss (4,687 ) 1,907 (2,780 ) Balance, September 30, 2019 $ (36,274 ) $ 494 $ (35,780 )

Business Segment Information

Business Segment Information	9 Months Ended
Business Segment Information	Sep. 30, 2019
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 investment management and administrative outsourcing platforms to retirement plan sponsors, healthcare systems and 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 internet-based investment services and advice platforms; entering new markets; and conducting other research and development activities. The information in the following tables is derived from the Company’s internal financial reporting used for corporate management purposes. There are no inter-segment revenues for the three and nine months ended September 30, 2019 and 2018 . 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, 2018 . The following tables highlight certain financial information about each of the Company’s business segments for the three months ended September 30, 2019 and 2018 : Private Banks Investment Advisors Institutional Investors Investment Managers Investments In New Businesses Total For the Three Months Ended September 30, 2019 Revenues $ 117,250 $ 103,033 $ 80,337 $ 112,186 $ 3,448 $ 416,254 Expenses 110,788 51,509 37,268 71,889 7,926 279,380 Operating profit (loss) $ 6,462 $ 51,524 $ 43,069 $ 40,297 $ (4,478 ) $ 136,874 Private Banks Investment Advisors Institutional Investors Investment Managers Investments In New Businesses Total For the Three Months Ended September 30, 2018 Revenues $ 118,449 $ 102,550 $ 83,466 $ 101,275 $ 2,942 $ 408,682 Expenses 116,471 53,287 40,497 65,296 5,769 281,320 Operating profit (loss) $ 1,978 $ 49,263 $ 42,969 $ 35,979 $ (2,827 ) $ 127,362 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 , 2019 and 2018 is as follows: 2019 2018 Total operating profit from segments $ 136,874 $ 127,362 Corporate overhead expenses (16,237 ) (14,942 ) Income from operations $ 120,637 $ 112,420 The following tables provide additional information for the three months ended September 30 , 2019 and 2018 pertaining to our business segments: Capital Expenditures (1) Depreciation 2019 2018 2019 2018 Private Banks $ 8,018 $ 7,999 $ 3,640 $ 3,427 Investment Advisors 4,468 3,927 1,162 1,168 Institutional Investors 1,070 962 393 410 Investment Managers 5,311 4,104 1,793 1,796 Investments in New Businesses 379 287 101 137 Total from business segments $ 19,246 $ 17,279 $ 7,089 $ 6,938 Corporate overhead 663 460 320 317 $ 19,909 $ 17,739 $ 7,409 $ 7,255 (1) Capital expenditures include additions to property and equipment and capitalized software. Amortization 2019 2018 Private Banks $ 7,322 $ 6,943 Investment Advisors 2,609 2,445 Institutional Investors 440 427 Investment Managers 2,334 2,346 Investments in New Businesses 185 186 Total from business segments $ 12,890 $ 12,347 Corporate overhead 57 58 $ 12,947 $ 12,405 The following tables highlight certain financial information about each of the Company’s business segments for the nine months ended September 30, 2019 and 2018 : Private Banks Investment Advisors Institutional Investors Investment Managers Investments In New Businesses Total For the Nine Months Ended September 30, 2019 Revenues $ 351,601 $ 297,916 $ 241,559 $ 326,037 $ 9,547 $ 1,226,660 Expenses 329,540 154,569 115,383 209,326 20,663 829,481 Operating profit (loss) $ 22,061 $ 143,347 $ 126,176 $ 116,711 $ (11,116 ) $ 397,179 Private Banks Investment Advisors Institutional Investors Investment Managers Investments In New Businesses Total For the Nine Months Ended September 30, 2018 Revenues $ 361,739 $ 301,632 $ 252,391 $ 295,696 $ 7,652 $ 1,219,110 Expenses 343,515 158,792 122,617 191,955 16,807 833,686 Operating profit (loss) $ 18,224 $ 142,840 $ 129,774 $ 103,741 $ (9,155 ) $ 385,424 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, 2019 and 2018 is as follows: 2019 2018 Total operating profit from segments $ 397,179 $ 385,424 Corporate overhead expenses (52,845 ) (46,398 ) Income from operations $ 344,334 $ 339,026 The following tables provide additional information for the nine months ended September 30, 2019 and 2018 pertaining to our business segments: Capital Expenditures (1) Depreciation 2019 2018 2019 2018 Private Banks $ 25,240 $ 27,767 $ 10,774 $ 10,069 Investment Advisors 12,973 12,471 3,506 3,378 Institutional Investors 2,990 2,926 1,212 1,310 Investment Managers 13,535 9,994 5,384 5,411 Investments in New Businesses 964 731 302 442 Total from business segments $ 55,702 $ 53,889 $ 21,178 $ 20,610 Corporate Overhead 1,634 1,134 984 905 $ 57,336 $ 55,023 $ 22,162 $ 21,515 (1) Capital expenditures include additions to property and equipment and capitalized software. Amortization 2019 2018 Private Banks $ 21,680 $ 20,317 Investment Advisors 7,682 7,203 Institutional Investors 1,300 1,281 Investment Managers 7,019 7,036 Investments in New Businesses 555 410 Total from business segments $ 38,236 $ 36,247 Corporate Overhead 171 173 $ 38,407 $ 36,420

Income Taxes

Income Taxes	9 Months Ended
Income Taxes	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The gross liability for unrecognized tax benefits at September 30, 2019 and December 31, 2018 was $14,627 and $14,367 , respectively, exclusive of interest and penalties, of which $14,183 and $13,774 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, 2019 and December 31, 2018 , the combined amount of accrued interest and penalties related to tax positions taken on tax returns was $1,520 and $1,289 , respectively. September 30, 2019 December 31, 2018 Gross liability for unrecognized tax benefits, exclusive of interest and penalties $ 14,627 $ 14,367 Interest and penalties on unrecognized benefits 1,520 1,289 Total gross uncertain tax positions $ 16,147 $ 15,656 Amount included in Current liabilities $ 1,008 $ 3,131 Amount included in Other long-term liabilities 15,139 12,525 $ 16,147 $ 15,656 The Company's effective income tax rate for the three and nine months ended September 30, 2019 and 2018 differs from the federal income tax statutory rate due to the following: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Statutory rate 21.0 % 21.0 % 21.0 % 21.0 % State taxes, net of federal tax benefit 2.6 2.3 2.6 2.3 Foreign tax expense and tax rate differential (0.3 ) (0.2 ) (0.2 ) (0.2 ) Tax benefit from stock option exercises (2.2 ) (1.4 ) (1.5 ) (4.8 ) Expiration of the statute of limitations (1.2 ) (1.0 ) (0.4 ) (0.3 ) Provision-to-return adjustment (0.6 ) (2.3 ) (0.2 ) (0.8 ) Other, net (0.4 ) 0.2 (0.3 ) — 18.9 % 18.6 % 21.0 % 17.2 % The increase in the Company's effective tax rate for the nine months ended September 30, 2019 was primarily due to reduced tax benefits related to the lower volume of stock option exercises as compared to the nine months ended September 30, 2018. 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 2015 and is no longer subject to state, local or foreign income tax examinations by authorities for years before 2014 . The Company estimates it will recognize $1,008 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
Commitments and Contingencies	Sep. 30, 2019
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, 2019 and December 31, 2018 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 and is procedurally the most advanced of the cases. SEI and SPTC filed exceptions, which the Court granted in part, dismissing claims under the Louisiana Unfair Trade Practices Act and permitting the claims under the Louisiana Securities Law to go forward. On March 11, 2013, newly-added insurance carrier defendants removed the case to the United States District Court for the Middle District of Louisiana. On August 7, 2013, the Judicial Panel on Multidistrict Litigation transferred the matter to the Northern District of Texas where MDL 2099, In re: Stanford Entities Securities Litigation (“the Stanford MDL”), is pending. On September 22, 2015, the District Court on the motion of SEI and SPTC dismissed plaintiffs’ claims for primary liability under Section 714(A) of the Louisiana Securities Law, but declined to dismiss plaintiffs’ claims for secondary liability under Section 714(B) of the Louisiana Securities Law based on the allegations pled by plaintiffs. On November 4, 2015, the District Court granted SEI and SPTC's motion to dismiss plaintiffs' claims under Section 712(D) of the Louisiana Securities Law. Consequently, the only claims of plaintiffs remaining in Lillie are plaintiffs' claims for secondary liability against SEI and SPTC under Section 714(B) of the Louisiana Securities Law. On May 2, 2016, the District Court certified the class as being "all persons for whom Stanford Trust Company purchased or renewed Stanford Investment Bank Limited certificates of deposit in Louisiana between January 1, 2007 and February 13, 2009". Notice of the pendency of the class action was mailed to potential class members on October 4, 2016. On December 1, 2016, 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 (“ Ahders Complaint”), alleging claims essentially the same as those in Lillie . In January 2017, the Judicial Panel on Multidistrict Litigation transferred the Ahders proceeding to the Northern District of Texas and the Stanford MDL. During February 2017, SEI filed its response to the Ahders Complaint, and in March 2017 the District Court for the Northern District of Texas approved the stipulated dismissal of all claims in this Complaint predicated on Section 712(D) or Section 714(A) of the Louisiana Securities Law. 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. Limited discovery and motions practice have occurred, including SEI and SPTC’s filing of a dispositive summary judgment motion in the Lillie proceeding. On January 31, 2019, the Judicial Panel on Multidistrict Litigation remanded the Lillie and Ahders proceedings to the Middle District of Louisiana. On July 9, 2019, the District Court issued an order granting SEI’s Summary Judgment Motion to dismiss the remaining Section 714(B) claim in the Lillie proceeding and denying Plaintiffs’ Motion for Continuance of SEI and SPTC’s Motion for Summary Judgment pursuant to Rule 56(d). On July 16, 2019, SEI and SPTC filed a Motion for Summary Judgment pursuant to Rule 56(d) in the Ahders proceeding to have the remaining Section 714(B) claim dismissed. On July 17, 2019, Plaintiffs filed a Motion for Reconsideration and/or New Trial as to the July 9, 2019 Ruling and Order (ECF 146) by the Honorable Brian A. Jackson denying a continuance of SEI’s Motion for Summary Judgment pursuant to Rule 56(d). The Court denied Plaintiffs’ Motion and entered a Final Judgment in favor of SEI on August 15, 2019. On August 27, 2019, Plaintiffs filed a Notice of Appeal to the United States Court of Appeal for the Fifth Circuit of the District Court's dismissal of the matter. Plaintiffs’ Motion in Support of the Notice of Appeal must be filed with the Court by November 20, 2019. If Plaintiffs’ Motion in Support of Appeal is filed, SEI intends to contest the Plaintiffs' appeal. 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. SEI Capital Accumulation Plan Litigation On September 28, 2018, a class action complaint was filed in the United States District Court for the Eastern District of Pennsylvania by Gordon Stevens, individually and as the representative of similarly situated persons, and on behalf of the SEI Capital Accumulation Plan (the “Plan”) naming the Company and its affiliated and/or related entities SEI Investments Management Corporation, SEI Capital Accumulation Plan Design Committee, SEI Capital Accumulation Plan Investment Committee, SEI Capital Accumulation Plan Administration Committee, and John Does 1-30 as defendants (the “Stevens Complaint”). The Stevens Compliant seeks unspecified damages for defendants’ breach of fiduciary duties under ERISA with respect to selecting and monitoring the Plan’s investment options and by retaining affiliated investment products in the Plan. Although SEI believes its defenses against the plaintiff’s allegations were valid, the Company agreed to settle this matter in the very early stages of the litigation in order to avoid the high cost of protracted class-action litigation and internal distractions such cases bring. The written settlement agreement was submitted to the Court on July 26, 2019, and is a matter of public record. A Preliminary Approval Order approving the settlement agreement was issued by the Court and the Court has scheduled a fairness hearing for December 18, 2019. The settlement agreement will not be finalized until the Court has issued a final approval after the December 18, 2019. The Company expects final Court approval of the settlement by year-end. The Company expects the financial impact of the settlement agreement to be immaterial. Other Matters The Company is also a party to various other 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.

Business Acquisition

Business Acquisition	9 Months Ended
Business Acquisition	Sep. 30, 2019
Business Combinations [Abstract]
Business Acquisition	Business Acquisition On April 2, 2018 , the Company acquired all ownership interests of Huntington Steele, LLC (Huntington Steele), a registered investment advisor based in Seattle, Washington servicing the ultra-high-net-worth market. The total purchase price for Huntington Steele was $17,914 , which includes $5,794 in cash consideration, net of $125 in cash acquired, and a contingent purchase price of $12,120 . The contingent purchase price consists of amounts payable to the sellers upon the attainment of specified financial measures determined at various intervals occurring between 2019 and 2023. The Company made a payment of $433 to the sellers during the nine months ended September 30, 2019. As of September 30, 2019 , the current portion of the contingent purchase price of $535 is included in Accrued liabilities on the accompanying Balance Sheet. The long-term portion of the contingent consideration of $11,152 is included in Other long-term liabilities on the accompanying Balance Sheet.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
Goodwill and Intangible Assets	Sep. 30, 2019
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 (See Note 12 ). 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. 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 the Company's goodwill during the nine months ended September 30, 2019 . The Company recognized $2,763 and $2,617 of amortization expense related to the intangible assets acquired through the acquisitions of Huntington Steele and Archway during the nine months ended September 30, 2019 and 2018 , respectively.

Revenues from Contracts with Cu

Revenues from Contracts with Customers	9 Months Ended
Revenues from Contracts with Customers	Sep. 30, 2019
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 total average daily 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 Company’s business segments for the three months ended September 30, 2019 and 2018 : Private Banks Investment Advisors Institutional Investors Investment Managers Investments In New Businesses Total Major Product Lines: For the Three Months Ended September 30, 2019 Investment management fees from pooled investment products $ 34,074 $ 72,150 $ 13,602 $ 161 $ 323 $ 120,310 Investment management fees from investment management agreements 314 26,240 66,373 — 3,099 96,026 Investment operations fees 434 — — 102,543 — 102,977 Investment processing fees - PaaS 43,462 — — — — 43,462 Investment processing fees - SaaS 34,018 — — 2,789 — 36,807 Professional services fees 3,533 — — 1,398 — 4,931 Account fees and other 1,415 4,643 362 5,295 26 11,741 Total revenues $ 117,250 $ 103,033 $ 80,337 $ 112,186 $ 3,448 $ 416,254 Primary Geographic Markets: United States $ 76,864 $ 103,033 $ 63,405 $ 104,859 $ 3,448 $ 351,609 United Kingdom 24,604 — 12,717 — — 37,321 Canada 10,985 — 1,743 — — 12,728 Ireland 4,797 — 2,310 7,327 — 14,434 Other — — 162 — — 162 Total revenues $ 117,250 $ 103,033 $ 80,337 $ 112,186 $ 3,448 $ 416,254 Private Banks Investment Advisors Institutional Investors Investment Managers Investments In New Businesses Total Major Product Lines: For the Three Months Ended September 30, 2018 Investment management fees from pooled investment products $ 34,897 $ 73,663 $ 14,614 $ 206 $ 267 $ 123,647 Investment management fees from investment management agreements 197 24,525 68,318 79 2,641 95,760 Investment operations fees 381 — — 92,185 — 92,566 Investment processing fees - PaaS 44,836 — — 624 — 45,460 Investment processing fees - SaaS 32,925 — — 2,417 — 35,342 Professional services fees 3,408 — — 1,792 — 5,200 Account fees and other 1,805 4,362 534 3,972 34 10,707 Total revenues $ 118,449 $ 102,550 $ 83,466 $ 101,275 $ 2,942 $ 408,682 Primary Geographic Markets: United States $ 73,188 $ 102,550 $ 64,601 $ 95,132 $ 2,942 $ 338,413 United Kingdom 28,647 — 13,817 — — 42,464 Canada 11,730 — 1,895 — — 13,625 Ireland 4,884 — 2,828 6,143 — 13,855 Other — — 325 — — 325 Total revenues $ 118,449 $ 102,550 $ 83,466 $ 101,275 $ 2,942 $ 408,682 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, 2019 and 2018 : Private Banks Investment Advisors Institutional Investors Investment Managers Investments In New Businesses Total Major Product Lines: For the Nine Months Ended September 30, 2019 Investment management fees from pooled investment products $ 100,498 $ 208,860 $ 41,062 $ 550 $ 957 $ 351,927 Investment management fees from investment management agreements 1,299 75,526 199,620 — 8,510 284,955 Investment operations fees 1,172 — — 297,342 — 298,514 Investment processing fees - PaaS 130,529 — — — — 130,529 Investment processing fees - SaaS 103,502 — — 7,931 — 111,433 Professional services fees 9,896 — — 4,363 — 14,259 Account fees and other 4,705 13,530 877 15,851 80 35,043 Total revenues $ 351,601 $ 297,916 $ 241,559 $ 326,037 $ 9,547 $ 1,226,660 Primary Geographic Markets: United States $ 229,207 $ 297,916 $ 189,383 $ 304,711 $ 9,547 $ 1,030,764 United Kingdom 75,649 — 39,323 — — 114,972 Canada 32,527 — 5,178 — — 37,705 Ireland 14,218 — 6,977 21,326 — 42,521 Other — — 698 — — 698 Total revenues $ 351,601 $ 297,916 $ 241,559 $ 326,037 $ 9,547 $ 1,226,660 Private Banks Investment Advisors Institutional Investors Investment Managers Investments In New Businesses Total Major Product Lines: For the Nine Months Ended September 30, 2018 Investment management fees from pooled investment products $ 105,251 $ 218,562 $ 45,819 $ 445 $ 729 $ 370,806 Investment management fees from investment management agreements 609 70,678 205,202 242 6,824 283,555 Investment operations fees 1,138 — — 267,951 — 269,089 Investment processing fees - PaaS 133,336 — — 1,749 — 135,085 Investment processing fees - SaaS 102,980 — — 7,152 — 110,132 Professional services fees 13,022 — — 5,660 — 18,682 Account fees and other 5,403 12,392 1,370 12,497 99 31,761 Total revenues $ 361,739 $ 301,632 $ 252,391 $ 295,696 $ 7,652 $ 1,219,110 Primary Geographic Markets: United States $ 226,990 $ 301,632 $ 193,417 $ 279,736 $ 7,652 $ 1,009,427 United Kingdom 85,177 — 42,498 — — 127,675 Canada 34,847 — 6,700 — — 41,547 Ireland 14,725 — 8,282 15,960 — 38,967 Other — — 1,494 — — 1,494 Total revenues $ 361,739 $ 301,632 $ 252,391 $ 295,696 $ 7,652 $ 1,219,110 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 average 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 average 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 average 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 a monthly fee plus additional fees determined on a per-account or per-transaction basis. Contractual fees can also be stated as 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 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. Revenue is recognized by the Company when the performance obligations are satisfied and transfer of control to the client is completed. The majority of the Company’s performance obligations are satisfied and control is transferred to the client continuously. Therefore, revenue is recognized on a monthly basis. The amount of revenue recognized reflects the amount of consideration expected to be received by the Company in exchange for satisfied performance obligations. The Company does not disclose the value of unsatisfied performance obligations as the majority of its contracts relate to: 1) contracts with an original term of one year or less; 2) contracts for which the Company recognizes revenue at the amount to which it has the right to invoice for services performed; and 3) contracts that are based on the value of assets under management or administration.

Leases

Leases	9 Months Ended
Leases	Sep. 30, 2019
Leases [Abstract]
Leases	Leases The Company has operating leases for corporate facilities and equipment. The Company's expense related to leases during the three and nine months ended September 30, 2019 was $2,502 and $7,599 , respectively, and is included in Facilities, supplies and other costs on the accompanying Consolidated Statement of Operations. The Company's future minimum lease payments under non-cancelable leases as of September 30, 2019 are as follows: 2019 (excluding the nine months ended September 30, 2019) $ 2,515 2020 8,955 2021 7,657 2022 7,369 2023 7,374 Thereafter 16,726 Total future minimum lease payments 50,596 Less: Imputed interest (4,892 ) Total $ 45,704 The following table provides supplemental Consolidated Balance Sheet information related to the Company's leases: September 30, 2019 Current portion of long-term operating lease liabilities $ 7,888 Long-term operating lease liabilities 37,816 Total operating lease liabilities $ 45,704 Weighted average remaining lease term 6.5 years Weighted average discount rate 2.66 % The following table provides supplemental cash flow information related to the Company's leases: For the Nine Months Ended September 30, 2019 Cash paid for amounts included in the measurement of lease liabilities $ 8,053 Right-of-use assets obtained in exchange for lease obligations 4,178

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policy)	9 Months Ended
Summary of Significant Accounting Policies (Policy)	Sep. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States of America. Certain financial information and accompanying note disclosure normally included in the Company’s Annual Report on Form 10-K 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, 2019 , the results of operations for the three and nine months ended September 30, 2019 and 2018 , and cash flows for the nine -month periods ended September 30, 2019 and 2018 . 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, 2018 . The Company adopted the requirements of the Accounting Standards Update (ASU) No. 2016-2 Leases (Topic 842) (Accounting Standards Codifications (ASC) 842 (ASC 842)) using the modified retrospective method during the nine months ended September 30, 2019 . As a result of the adoption of ASC 842, the Company recorded additional lease assets and net lease liabilities of $44,169 as of January 1, 2019. Upon implementation, the Company elected the package of practical expedients permitted under the transition guidance within the new standard which allowed the Company to carryforward the historical lease identification, classification and initial direct cost. ASC 842 did not materially impact the Company’s consolidated net income or consolidated cash flows (see following caption "Leases"). With the exception of the adoption of ASC 842, there have been no significant changes in significant accounting policies during the nine months ended September 30, 2019 as compared to the significant accounting policies described in the Company's Annual Report on Form 10-K for the year ended December 31, 2018 .
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. The entities either do not meet the definition of a VIE or the Company does not hold a variable interest in the entities. The entities either qualify for the money market scope exception, or are entities in which the Company’s asset management, distribution, administration and custodial fees are commensurate with the services provided and include fair terms and conditions, or are entities that are limited partnerships which have substantive kick-out rights. The Company acts as a fiduciary and does not hold any other interests other than insignificant seed money investments in the pooled investment vehicles. For this reason, the Company also concluded that it is not required to consolidate the pooled investment vehicles under the voting interest entity model.
Revenue Recognition	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).
Cash and Cash Equivalents	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. Cash and Cash Equivalents Cash and cash equivalents includes $319,977 and $315,840 at September 30, 2019 and December 31, 2018 , respectively, primarily invested in SEI-sponsored open-ended money market mutual funds. The SEI-sponsored mutual funds are Level 1 assets.
Restricted Cash	Restricted Cash Restricted cash includes $3,000 at September 30, 2019 and December 31, 2018 segregated for regulatory purposes related to trade-execution services conducted by SEI Investments (Europe) Limited. Restricted cash also includes $100 and $514 at September 30, 2019 and December 31, 2018 , respectively, 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.
Leases	Leases The Company determines if an arrangement is a lease at the inception of the contract. The Company's operating leases are included in Operating lease right-of-use (ROU) assets, Current portion of long-term operating lease liabilities, and Long-term operating lease liabilities on the accompanying Consolidated Balance Sheet. The operating lease ROU assets and operating lease liabilities are recognized based on the present value of future minimum lease payments over the lease term at commencement date. As most of the Company’s leases do not provide an implicit interest rate, the Company utilizes an estimated incremental borrowing rate based on the information available at commencement date in determining the present value of future payments. In determining the discount rate used in the present value calculation, the Company has elected to apply the portfolio approach for leases of equipment provided the leases commenced at or around the same time. This election allows the Company to account for leases at a portfolio level provided that the resulting accounting at this level would not differ materially from the accounting at the individual lease level. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. The Company has elected to account for lease and non-lease components separately. Operating lease ROU assets include all contractual lease payments and initial direct costs incurred, less any lease incentives. Facility leases generally only contain lease expense and non-component items such as taxes and pass through charges. Only the lease components are included in the ROU assets and lease liabilities. Additionally, the Company has elected not to apply the recognition requirements of ASC 842 to leases which have a lease term of less than one year at the commencement date. The majority of the Company's leases for corporate facilities and equipment contain terms for renewal and extension of the lease agreement. The exercise of lease renewal options is generally at the Company’s sole discretion. The Company includes the lease extensions when it is reasonably certain the Company will exercise the extension. The Company’s lease agreements do not contain any material variable lease payments, material residual value guarantees or any material restrictive covenants. The Company does not currently have any finance leases.
New Accounting Pronouncements	New Accounting Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13) and a subsequent amendment ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments (ASU 2019-04) in April 2019. ASU 2016-13 requires that expected credit losses relating to financial assets measured on an amortized cost basis and available-for-sale debt securities be recorded through an allowance for credit losses. ASU 2016-13 limits the amount of credit losses to be recognized for available-for-sale debt securities to the amount by which carrying value exceeds fair value and also requires the reversal of previously recognized credit losses if fair value increases. ASU 2019-04 provides certain improvements to ASU 2016-13. ASU 2016-13 and ASU 2019-04 become effective for the Company during the first quarter of 2020. Early adoption is permitted. The Company is currently finalizing its evaluation of ASU 2016-13 and ASU 2019-04 and does not believe the adoption of the updated standards will have a material impact on its consolidated financial statements and related disclosures. In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment (ASU 2017-04). The objective of ASU 2017-04 is to simplify the subsequent measurement of goodwill by entities performing their annual goodwill impairment tests by comparing the fair value of a reporting unit, including income tax effects from any tax-deductible goodwill, with its carrying amount and recognizing an impairment charge for the amount by which the carrying amount exceeds fair value. ASU 2017-04 is effective for the Company beginning in the first quarter of 2020. Early adoption is permitted. The Company does not believe the adoption of ASU 2017-04 will have a material impact on its consolidated financial statements and related disclosures. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement (ASU 2018-13) which modifies the disclosure requirements on fair value measurements. ASU 2018-13 is effective for the Company beginning in the first quarter of 2020. The Company is currently finalizing its evaluation of ASU 2018-13 and does not believe the adoption of the updated standard will have a material impact on its consolidated financial statements and related disclosures. In October 2018, the FASB issued ASU 2018-17, Consolidation (Topic 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities (ASU 2018-17). The new standard changes how entities evaluate decision-making fees under the variable interest entity guidance. ASU 2018-17 is effective for the Company beginning in the first quarter of 2020. The Company does not believe the adoption of ASU 2018-17 will have a material impact on its consolidated financial statements and related disclosures.
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 Government National Mortgage Association (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 , 2019 were consistent with those as described in our Annual Report on Form 10-K at December 31, 2018 . The Company had no Level 3 financial assets at September 30, 2019 or December 31, 2018
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 and losses 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
Summary of Significant Accounting Policies (Tables)	Sep. 30, 2019
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, 2019 and 2018 are: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Net income $ 132,168 $ 128,319 $ 372,689 $ 389,834 Shares used to compute basic earnings per common share 150,855,000 156,283,000 152,009,000 157,086,000 Dilutive effect of stock options 3,372,000 4,228,000 3,302,000 4,967,000 Shares used to compute diluted earnings per common share 154,227,000 160,511,000 155,311,000 162,053,000 Basic earnings per common share $ 0.88 $ 0.82 $ 2.45 $ 2.48 Diluted earnings per common share $ 0.86 $ 0.80 $ 2.40 $ 2.41
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 : 2019 2018 Net income $ 372,689 $ 389,834 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation 22,162 21,515 Amortization 38,407 36,420 Equity in earnings of unconsolidated affiliate (112,758 ) (123,406 ) Distributions received from unconsolidated affiliate 123,663 138,216 Stock-based compensation 15,555 16,396 Provision for losses on receivables 593 (29 ) Deferred income tax expense (1,405 ) 8,378 Net (gain) loss from investments (2,121 ) 460 Change in long-term income taxes payable — (9,859 ) Change in other long-term liabilities 2,077 1,930 Change in other assets (56 ) (4,214 ) Contract costs capitalized, net of amortization (4,499 ) (3,463 ) Other (721 ) (99 ) Change in current assets and liabilities (Increase) decrease in Receivables from investment products (2,271 ) 2,263 Receivables (34,589 ) (44,878 ) Other current assets 729 (5,955 ) (Decrease) increase in Accounts payable (2,208 ) 3,893 Accrued liabilities (34,087 ) (9,717 ) Deferred revenue 375 213 Total adjustments 8,846 28,064 Net cash provided by operating activities $ 381,535 $ 417,898

Investment In Unconsolidated _2

Investment In Unconsolidated Affiliate (Tables)	9 Months Ended
Investment In Unconsolidated Affiliate (Tables)	Sep. 30, 2019
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, 2019 2018 2019 2018 Revenues $ 121,232 $ 133,921 $ 365,164 $ 397,750 Net income 96,699 107,284 289,918 317,295 Condensed Balance Sheets September 30, 2019 December 31, 2018 Current assets $ 138,320 $ 138,083 Non-current assets 4,721 1,165 Total assets $ 143,041 $ 139,248 Current liabilities $ 75,192 $ 47,874 Non-current liabilities 4,738 — Partners’ capital 63,111 91,374 Total liabilities and partners’ capital $ 143,041 $ 139,248

Composition of Certain Financ_2

Composition of Certain Financial Statement Captions (Tables)	9 Months Ended
	Sep. 30, 2019
Items Included in Consolidated Statement of Financial Condition [Abstract]
Receivables	Receivables on the accompanying Consolidated Balance Sheets consist of: September 30, 2019 December 31, 2018 Trade receivables $ 91,372 $ 76,362 Fees earned, not billed 241,340 226,001 Other receivables 17,931 13,691 350,643 316,054 Less: Allowance for doubtful accounts (1,311 ) (718 ) $ 349,332 $ 315,336
Property And Equipment	Property and Equipment on the accompanying Consolidated Balance Sheets consists of: September 30, 2019 December 31, 2018 Buildings $ 162,677 $ 160,796 Equipment 119,585 126,954 Land 10,830 10,772 Purchased software 142,693 139,245 Furniture and fixtures 18,478 18,103 Leasehold improvements 19,656 18,959 Construction in progress 27,042 9,240 500,961 484,069 Less: Accumulated depreciation (346,377 ) (338,206 ) Property and Equipment, net $ 154,584 $ 145,863
Accrued Liabilities	Accrued liabilities on the accompanying Consolidated Balance Sheets consist of: September 30, 2019 December 31, 2018 Accrued employee compensation $ 73,997 $ 97,603 Accrued consulting, outsourcing and professional fees 27,491 31,000 Accrued sub-advisory, distribution and other asset management fees 45,495 42,583 Accrued dividend payable — 50,761 Other accrued liabilities 46,936 57,687 Total accrued liabilities $ 193,919 $ 279,634

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
Fair Value Measurements (Tables)	Sep. 30, 2019
Fair Value Disclosures [Abstract]
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, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Equity available-for-sale securities $ 11,313 $ 11,313 $ — Fixed-income available-for-sale securities 90,267 — 90,267 Fixed-income securities owned 32,862 — 32,862 Investment funds sponsored by LSV (1) 5,533 $ 139,975 $ 11,313 $ 123,129 Fair Value Measurements at the End of the Reporting Period Using Assets December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Equity available-for-sale securities $ 10,218 $ 10,218 $ — Fixed-income available-for-sale securities 101,683 — 101,683 Fixed-income securities owned 30,892 — 30,892 Investment funds sponsored by LSV (1) 4,887 $ 147,680 $ 10,218 $ 132,575 (1) The fair value amounts presented in the tables above are intended to permit reconciliation of the fair value hierarchy to the amounts presented on the accompanying Consolidated Balance Sheets (See Note 5

Marketable Securities (Tables)

Marketable Securities (Tables)	9 Months Ended
Marketable Securities (Tables)	Sep. 30, 2019
Marketable Securities [Abstract]
Investments Available For Sale	Investments available for sale classified as non-current assets consist of: At September 30, 2019 Cost Amount Gross Unrealized Gains Gross Unrealized (Losses) Fair Value SEI-sponsored mutual funds $ 7,477 $ 105 $ (411 ) $ 7,171 Equities and other mutual funds 3,476 666 — 4,142 Debt securities 89,625 642 — 90,267 $ 100,578 $ 1,413 $ (411 ) $ 101,580 At December 31, 2018 Cost Amount Gross Unrealized Gains Gross Unrealized (Losses) Fair Value SEI-sponsored mutual funds $ 7,446 $ — $ (788 ) $ 6,658 Equities and other mutual funds 3,434 126 — 3,560 Debt securities 103,518 — (1,835 ) 101,683 $ 114,398 $ 126 $ (2,623 ) $ 111,901

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	9 Months Ended
Shareholders' Equity (Tables)	Sep. 30, 2019
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, 2019 and 2018 , respectively, as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Stock-based compensation expense $ 5,453 $ 5,878 $ 15,555 $ 16,396 Less: Deferred tax benefit (1,042 ) (1,311 ) (2,959 ) (3,556 ) Stock-based compensation expense, net of tax $ 4,411 $ 4,567 $ 12,596 $ 12,840

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
Accumulated Other Comprehensive Income (Loss) (Tables)	Sep. 30, 2019
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 Gains (Losses) on Investments Accumulated Other Comprehensive Loss Balance, January 1, 2019 $ (31,587 ) $ (1,413 ) $ (33,000 ) Other comprehensive loss before reclassifications (4,687 ) 1,633 (3,054 ) Amounts reclassified from accumulated other comprehensive loss — 274 274 Net current-period other comprehensive loss (4,687 ) 1,907 (2,780 ) Balance, September 30, 2019 $ (36,274 ) $ 494 $ (35,780 )

Business Segment Information (T

Business Segment Information (Tables)	9 Months Ended
Business Segment Information (Tables)	Sep. 30, 2019
Segment Reporting [Abstract]
Schedule Of Financial Information About Business Segments	The following tables highlight certain financial information about each of the Company’s business segments for the three months ended September 30, 2019 and 2018 : Private Banks Investment Advisors Institutional Investors Investment Managers Investments In New Businesses Total For the Three Months Ended September 30, 2019 Revenues $ 117,250 $ 103,033 $ 80,337 $ 112,186 $ 3,448 $ 416,254 Expenses 110,788 51,509 37,268 71,889 7,926 279,380 Operating profit (loss) $ 6,462 $ 51,524 $ 43,069 $ 40,297 $ (4,478 ) $ 136,874 Private Banks Investment Advisors Institutional Investors Investment Managers Investments In New Businesses Total For the Three Months Ended September 30, 2018 Revenues $ 118,449 $ 102,550 $ 83,466 $ 101,275 $ 2,942 $ 408,682 Expenses 116,471 53,287 40,497 65,296 5,769 281,320 Operating profit (loss) $ 1,978 $ 49,263 $ 42,969 $ 35,979 $ (2,827 ) $ 127,362
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 , 2019 and 2018 is as follows: 2019 2018 Total operating profit from segments $ 136,874 $ 127,362 Corporate overhead expenses (16,237 ) (14,942 ) Income from operations $ 120,637 $ 112,420
Reconciliation of Other Significant Reconciling Items from Segments to Consolidated	The following tables provide additional information for the three months ended September 30 , 2019 and 2018 pertaining to our business segments: Capital Expenditures (1) Depreciation 2019 2018 2019 2018 Private Banks $ 8,018 $ 7,999 $ 3,640 $ 3,427 Investment Advisors 4,468 3,927 1,162 1,168 Institutional Investors 1,070 962 393 410 Investment Managers 5,311 4,104 1,793 1,796 Investments in New Businesses 379 287 101 137 Total from business segments $ 19,246 $ 17,279 $ 7,089 $ 6,938 Corporate overhead 663 460 320 317 $ 19,909 $ 17,739 $ 7,409 $ 7,255 (1) Capital expenditures include additions to property and equipment and capitalized software. Amortization 2019 2018 Private Banks $ 7,322 $ 6,943 Investment Advisors 2,609 2,445 Institutional Investors 440 427 Investment Managers 2,334 2,346 Investments in New Businesses 185 186 Total from business segments $ 12,890 $ 12,347 Corporate overhead 57 58 $ 12,947 $ 12,405 The following tables highlight certain financial information about each of the Company’s business segments for the nine months ended September 30, 2019 and 2018 : Private Banks Investment Advisors Institutional Investors Investment Managers Investments In New Businesses Total For the Nine Months Ended September 30, 2019 Revenues $ 351,601 $ 297,916 $ 241,559 $ 326,037 $ 9,547 $ 1,226,660 Expenses 329,540 154,569 115,383 209,326 20,663 829,481 Operating profit (loss) $ 22,061 $ 143,347 $ 126,176 $ 116,711 $ (11,116 ) $ 397,179 Private Banks Investment Advisors Institutional Investors Investment Managers Investments In New Businesses Total For the Nine Months Ended September 30, 2018 Revenues $ 361,739 $ 301,632 $ 252,391 $ 295,696 $ 7,652 $ 1,219,110 Expenses 343,515 158,792 122,617 191,955 16,807 833,686 Operating profit (loss) $ 18,224 $ 142,840 $ 129,774 $ 103,741 $ (9,155 ) $ 385,424 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, 2019 and 2018 is as follows: 2019 2018 Total operating profit from segments $ 397,179 $ 385,424 Corporate overhead expenses (52,845 ) (46,398 ) Income from operations $ 344,334 $ 339,026 The following tables provide additional information for the nine months ended September 30, 2019 and 2018 pertaining to our business segments: Capital Expenditures (1) Depreciation 2019 2018 2019 2018 Private Banks $ 25,240 $ 27,767 $ 10,774 $ 10,069 Investment Advisors 12,973 12,471 3,506 3,378 Institutional Investors 2,990 2,926 1,212 1,310 Investment Managers 13,535 9,994 5,384 5,411 Investments in New Businesses 964 731 302 442 Total from business segments $ 55,702 $ 53,889 $ 21,178 $ 20,610 Corporate Overhead 1,634 1,134 984 905 $ 57,336 $ 55,023 $ 22,162 $ 21,515 (1) Capital expenditures include additions to property and equipment and capitalized software. Amortization 2019 2018 Private Banks $ 21,680 $ 20,317 Investment Advisors 7,682 7,203 Institutional Investors 1,300 1,281 Investment Managers 7,019 7,036 Investments in New Businesses 555 410 Total from business segments $ 38,236 $ 36,247 Corporate Overhead 171 173 $ 38,407 $ 36,420

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
Income Taxes (Tables)	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Schedule Of Interest And Penalties	September 30, 2019 December 31, 2018 Gross liability for unrecognized tax benefits, exclusive of interest and penalties $ 14,627 $ 14,367 Interest and penalties on unrecognized benefits 1,520 1,289 Total gross uncertain tax positions $ 16,147 $ 15,656 Amount included in Current liabilities $ 1,008 $ 3,131 Amount included in Other long-term liabilities 15,139 12,525 $ 16,147 $ 15,656
Schedule of Effective Income Tax Rate Reconciliation	The Company's effective income tax rate for the three and nine months ended September 30, 2019 and 2018 differs from the federal income tax statutory rate due to the following: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 Statutory rate 21.0 % 21.0 % 21.0 % 21.0 % State taxes, net of federal tax benefit 2.6 2.3 2.6 2.3 Foreign tax expense and tax rate differential (0.3 ) (0.2 ) (0.2 ) (0.2 ) Tax benefit from stock option exercises (2.2 ) (1.4 ) (1.5 ) (4.8 ) Expiration of the statute of limitations (1.2 ) (1.0 ) (0.4 ) (0.3 ) Provision-to-return adjustment (0.6 ) (2.3 ) (0.2 ) (0.8 ) Other, net (0.4 ) 0.2 (0.3 ) — 18.9 % 18.6 % 21.0 % 17.2 %

Revenues from Contracts with _2

Revenues from Contracts with Customers (Tables)	9 Months Ended
Revenues from Contracts with Customers (Tables)	Sep. 30, 2019
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 Company’s business segments for the three months ended September 30, 2019 and 2018 : Private Banks Investment Advisors Institutional Investors Investment Managers Investments In New Businesses Total Major Product Lines: For the Three Months Ended September 30, 2019 Investment management fees from pooled investment products $ 34,074 $ 72,150 $ 13,602 $ 161 $ 323 $ 120,310 Investment management fees from investment management agreements 314 26,240 66,373 — 3,099 96,026 Investment operations fees 434 — — 102,543 — 102,977 Investment processing fees - PaaS 43,462 — — — — 43,462 Investment processing fees - SaaS 34,018 — — 2,789 — 36,807 Professional services fees 3,533 — — 1,398 — 4,931 Account fees and other 1,415 4,643 362 5,295 26 11,741 Total revenues $ 117,250 $ 103,033 $ 80,337 $ 112,186 $ 3,448 $ 416,254 Primary Geographic Markets: United States $ 76,864 $ 103,033 $ 63,405 $ 104,859 $ 3,448 $ 351,609 United Kingdom 24,604 — 12,717 — — 37,321 Canada 10,985 — 1,743 — — 12,728 Ireland 4,797 — 2,310 7,327 — 14,434 Other — — 162 — — 162 Total revenues $ 117,250 $ 103,033 $ 80,337 $ 112,186 $ 3,448 $ 416,254 Private Banks Investment Advisors Institutional Investors Investment Managers Investments In New Businesses Total Major Product Lines: For the Three Months Ended September 30, 2018 Investment management fees from pooled investment products $ 34,897 $ 73,663 $ 14,614 $ 206 $ 267 $ 123,647 Investment management fees from investment management agreements 197 24,525 68,318 79 2,641 95,760 Investment operations fees 381 — — 92,185 — 92,566 Investment processing fees - PaaS 44,836 — — 624 — 45,460 Investment processing fees - SaaS 32,925 — — 2,417 — 35,342 Professional services fees 3,408 — — 1,792 — 5,200 Account fees and other 1,805 4,362 534 3,972 34 10,707 Total revenues $ 118,449 $ 102,550 $ 83,466 $ 101,275 $ 2,942 $ 408,682 Primary Geographic Markets: United States $ 73,188 $ 102,550 $ 64,601 $ 95,132 $ 2,942 $ 338,413 United Kingdom 28,647 — 13,817 — — 42,464 Canada 11,730 — 1,895 — — 13,625 Ireland 4,884 — 2,828 6,143 — 13,855 Other — — 325 — — 325 Total revenues $ 118,449 $ 102,550 $ 83,466 $ 101,275 $ 2,942 $ 408,682 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, 2019 and 2018 : Private Banks Investment Advisors Institutional Investors Investment Managers Investments In New Businesses Total Major Product Lines: For the Nine Months Ended September 30, 2019 Investment management fees from pooled investment products $ 100,498 $ 208,860 $ 41,062 $ 550 $ 957 $ 351,927 Investment management fees from investment management agreements 1,299 75,526 199,620 — 8,510 284,955 Investment operations fees 1,172 — — 297,342 — 298,514 Investment processing fees - PaaS 130,529 — — — — 130,529 Investment processing fees - SaaS 103,502 — — 7,931 — 111,433 Professional services fees 9,896 — — 4,363 — 14,259 Account fees and other 4,705 13,530 877 15,851 80 35,043 Total revenues $ 351,601 $ 297,916 $ 241,559 $ 326,037 $ 9,547 $ 1,226,660 Primary Geographic Markets: United States $ 229,207 $ 297,916 $ 189,383 $ 304,711 $ 9,547 $ 1,030,764 United Kingdom 75,649 — 39,323 — — 114,972 Canada 32,527 — 5,178 — — 37,705 Ireland 14,218 — 6,977 21,326 — 42,521 Other — — 698 — — 698 Total revenues $ 351,601 $ 297,916 $ 241,559 $ 326,037 $ 9,547 $ 1,226,660 Private Banks Investment Advisors Institutional Investors Investment Managers Investments In New Businesses Total Major Product Lines: For the Nine Months Ended September 30, 2018 Investment management fees from pooled investment products $ 105,251 $ 218,562 $ 45,819 $ 445 $ 729 $ 370,806 Investment management fees from investment management agreements 609 70,678 205,202 242 6,824 283,555 Investment operations fees 1,138 — — 267,951 — 269,089 Investment processing fees - PaaS 133,336 — — 1,749 — 135,085 Investment processing fees - SaaS 102,980 — — 7,152 — 110,132 Professional services fees 13,022 — — 5,660 — 18,682 Account fees and other 5,403 12,392 1,370 12,497 99 31,761 Total revenues $ 361,739 $ 301,632 $ 252,391 $ 295,696 $ 7,652 $ 1,219,110 Primary Geographic Markets: United States $ 226,990 $ 301,632 $ 193,417 $ 279,736 $ 7,652 $ 1,009,427 United Kingdom 85,177 — 42,498 — — 127,675 Canada 34,847 — 6,700 — — 41,547 Ireland 14,725 — 8,282 15,960 — 38,967 Other — — 1,494 — — 1,494 Total revenues $ 361,739 $ 301,632 $ 252,391 $ 295,696 $ 7,652 $ 1,219,110

Leases (Tables)

Leases (Tables)	9 Months Ended
Leases (Tables)	Sep. 30, 2019
Leases [Abstract]
Schedule of Future Minimum Lease Payments	The Company's future minimum lease payments under non-cancelable leases as of September 30, 2019 are as follows: 2019 (excluding the nine months ended September 30, 2019) $ 2,515 2020 8,955 2021 7,657 2022 7,369 2023 7,374 Thereafter 16,726 Total future minimum lease payments 50,596 Less: Imputed interest (4,892 ) Total $ 45,704
Supplemental Consolidated Balance Sheet Information Related to Operating Leases	The following table provides supplemental Consolidated Balance Sheet information related to the Company's leases: September 30, 2019 Current portion of long-term operating lease liabilities $ 7,888 Long-term operating lease liabilities 37,816 Total operating lease liabilities $ 45,704 Weighted average remaining lease term 6.5 years Weighted average discount rate 2.66 %
Supplemental Cash Flow Information Related to Operating Leases	The following table provides supplemental cash flow information related to the Company's leases: For the Nine Months Ended September 30, 2019 Cash paid for amounts included in the measurement of lease liabilities $ 8,053 Right-of-use assets obtained in exchange for lease obligations 4,178

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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jan. 01, 2019	Dec. 31, 2018
Summary of Significant Accounting Policies [Line Items]
Operating Lease Right-of-Use Assets	$ 41,054		$ 41,054
Lease liabilities	45,704		45,704
Cash and cash equivalents invested in SEI-sponsored money market funds	767,809		767,809			$ 754,525
Restricted cash	3,100		3,100			3,514
Capitalized software development costs			26,821	$ 33,371
Net book value of capitalized software	$ 300,848		$ 300,848			309,500
Anti-dilutive employee stock options (in shares)	6,239	6,183	6,269	6,153
Anti-dilutive employee stock options (in USD per share)	$ 54.91	$ 53.38	$ 54.84	$ 53.15
SEI Wealth Platform
Summary of Significant Accounting Policies [Line Items]
Capitalized software development costs			$ 26,029	$ 32,526
Net book value of capitalized software	$ 283,128		283,128
Capitalized software in progress	51,781		51,781			42,238
Amortization expense of capitalized software			$ 31,567	29,723
SEI Wealth Platform \| Weighted Average
Summary of Significant Accounting Policies [Line Items]
Weighted Average Estimated Useful Life			8 years 4 months 24 days
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	319,977		$ 319,977			315,840
SEI Investments (Europe) Limited
Summary of Significant Accounting Policies [Line Items]
Restricted cash	3,000		3,000			3,000
SEI Investments Distribution Co. (SIDCO)
Summary of Significant Accounting Policies [Line Items]
Restricted cash	100		100			$ 514
SEI-Sponsored Open-Ended Money Market Mutual Funds
Summary of Significant Accounting Policies [Line Items]
Fees waived according to expense limitation agreements	$ 6,390	$ 6,525	$ 21,091	$ 19,551
Accounting Standards Update 2016-02
Summary of Significant Accounting Policies [Line Items]
Operating Lease Right-of-Use Assets					$ 44,169
Lease liabilities					$ 44,169

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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Accounting Policies [Abstract]
Net income	$ 132,168	$ 128,319	$ 372,689	$ 389,834
Shares used to compute basic earnings per common share (in shares)	150,855	156,283	152,009	157,086
Dilutive effect of stock options (in shares)	3,372	4,228	3,302	4,967
Shares used to compute diluted earnings per common share (in shares)	154,227	160,511	155,311	162,053
Basic earnings per common share (in USD per share)	$ 0.88	$ 0.82	$ 2.45	$ 2.48
Diluted earnings per common share (in USD per share)	$ 0.86	$ 0.80	$ 2.40	$ 2.41

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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Accounting Policies [Abstract]
Net income	$ 132,168	$ 128,319	$ 372,689	$ 389,834
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	7,409	7,255	22,162	21,515
Amortization	12,947	12,405	38,407	36,420
Equity in earnings of unconsolidated affiliate	(37,609)	(41,726)	(112,758)	(123,406)
Distributions received from unconsolidated affiliate			123,663	138,216
Stock-based compensation	$ 5,453	$ 5,878	15,555	16,396
Provision for losses on receivables			593	(29)
Deferred income tax expense			(1,405)	8,378
Net (gain) loss from investments			(2,121)	460
Change in long-term income taxes payable			0	(9,859)
Change in other long-term liabilities			2,077	1,930
Change in other assets			(56)	(4,214)
Contract costs capitalized, net of amortization			(4,499)	(3,463)
Other			(721)	(99)
(Increase) decrease in
Receivables from investment products			(2,271)	2,263
Receivables			(34,589)	(44,878)
Other current assets			729	(5,955)
(Decrease) increase in
Accounts payable			(2,208)	3,893
Accrued liabilities			(34,087)	(9,717)
Deferred revenue			375	213
Total adjustments			8,846	28,064
Net cash provided by operating activities			$ 381,535	$ 417,898

Investment In Unconsolidated _3

Investment In Unconsolidated Affiliate (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Investments in and Advances to Affiliates [Line Items]
Distributions received from unconsolidated affiliate			$ 123,663	$ 138,216
Company's share in the earnings of equity method investee	$ 37,609	$ 41,726	$ 112,758	123,406
LSV Asset Management
Investments in and Advances to Affiliates [Line Items]
Equity method investment, ownership percentage	38.90%		38.90%
Total investment in equity method investee	$ 41,437		$ 41,437
Distributions received from unconsolidated affiliate			123,663	138,216
Company's share in the earnings of equity method investee	$ 37,609	$ 41,726	$ 112,758	$ 123,406

Investment In Unconsolidated _4

Investment In Unconsolidated Affiliate (Statement of Operations) (Details) - LSV Asset Management - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Schedule of Equity Method Investments [Line Items]
Revenues	$ 121,232	$ 133,921	$ 365,164	$ 397,750
Net income	$ 96,699	$ 107,284	$ 289,918	$ 317,295

Investment in Unconsolidated _5

Investment in Unconsolidated Affiliate (Balance Sheets) (Details) - LSV Asset Management - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Current assets	$ 138,320	$ 138,083
Non-current assets	4,721	1,165
Total assets	143,041	139,248
Current liabilities	75,192	47,874
Non-current liabilities	4,738	0
Partners’ capital	63,111	91,374
Total liabilities and partners’ capital	$ 143,041	$ 139,248

Composition of Certain Financ_3

Composition of Certain Financial Statement Captions (Receivables) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Items Included in Consolidated Statement of Financial Condition [Abstract]
Trade receivables	$ 91,372	$ 76,362
Fees earned, not billed	241,340	226,001
Other receivables	17,931	13,691
Receivables, Gross, Current	350,643	316,054
Less: Allowance for doubtful accounts	(1,311)	(718)
Receivables, net	$ 349,332	$ 315,336

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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Property and Equipment [Line Items]
Property and Equipment, gross	$ 500,961		$ 500,961		$ 484,069
Less: Accumulated depreciation	(346,377)		(346,377)		(338,206)
Property and Equipment, net	154,584		154,584		145,863
Depreciation expense	7,409	$ 7,255	22,162	$ 21,515
Buildings
Property and Equipment [Line Items]
Property and Equipment, gross	162,677		162,677		160,796
Equipment
Property and Equipment [Line Items]
Property and Equipment, gross	119,585		119,585		126,954
Land
Property and Equipment [Line Items]
Property and Equipment, gross	10,830		10,830		10,772
Purchased software
Property and Equipment [Line Items]
Property and Equipment, gross	142,693		142,693		139,245
Furniture and fixtures
Property and Equipment [Line Items]
Property and Equipment, gross	18,478		18,478		18,103
Leasehold improvements
Property and Equipment [Line Items]
Property and Equipment, gross	19,656		19,656		18,959
Construction in progress
Property and Equipment [Line Items]
Property and Equipment, gross	$ 27,042		$ 27,042		$ 9,240

Composition of Certain Financ_5

Composition of Certain Financial Statement Captions (Deferred Contract Costs) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Items Included in Consolidated Statement of Financial Condition [Abstract]
Deferred contract costs	$ 28,506,000		$ 28,506,000		$ 24,007,000
Capitalized contract cost, amount capitalized during period	$ 4,575,000	$ 1,400,000	7,673,000	$ 5,483,000
Amortization of deferred contract costs			3,174,000	$ 2,020,000
Capitalized contract cost impairment			$ 0

Composition of Certain Financ_6

Composition of Certain Financial Statement Captions (Accrued Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Items Included in Consolidated Statement of Financial Condition [Abstract]
Accrued employee compensation	$ 73,997	$ 97,603
Accrued consulting, outsourcing and professional fees	27,491	31,000
Accrued sub-advisory, distribution and other asset management fees	45,495	42,583
Accrued dividend payable	0	50,761
Other accrued liabilities	46,936	57,687
Total accrued liabilities	$ 193,919	$ 279,634

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	$ 5,533	$ 4,887
Fixed-income securities owned	32,862	30,892
Assets, fair value	139,975	147,680
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	11,313	10,218
Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fixed-income securities owned	32,862	30,892
Assets, fair value	123,129	132,575
SEI Sponsored Mutual Funds, Equities and Other Mutual Funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	11,313	10,218
SEI Sponsored Mutual Funds, Equities and Other Mutual Funds \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	11,313	10,218
SEI Sponsored Mutual Funds, Equities and Other Mutual Funds \| Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	0	0
Fixed income securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities	90,267	101,683
Fixed income 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
Fixed income securities \| Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale securities	90,267	101,683
Investment funds sponsored by LSV
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities, FV-NI	$ 5,533	$ 4,887

Marketable Securities (Investme

Marketable Securities (Investments Available For Sale) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Equity securities, FV-NI	$ 5,533	$ 4,887
Investments Available for sale, Cost Amount	100,578	114,398
Investments Available for sale, Gross Unrealized Gains	1,413	126
Investments Available for sale, Gross Unrealized (Losses)	(411)	(2,623)
Investments Available for sale, Fair Value	101,580	111,901
SEI-sponsored mutual funds
Debt Securities, Available-for-sale [Line Items]
Equity securities, FV-NI, Cost Amount	7,477	7,446
Equity securities, FV-NI, Gross Unrealized Gains	105	0
Equity securities, FV-NI, Gross Unrealized (Losses)	(411)	(788)
Equity securities, FV-NI	7,171	6,658
Equities and other mutual funds
Debt Securities, Available-for-sale [Line Items]
Equity securities, FV-NI, Cost Amount	3,476	3,434
Equity securities, FV-NI, Gross Unrealized Gains	666	126
Equity securities, FV-NI, Gross Unrealized (Losses)	0	0
Equity securities, FV-NI	4,142	3,560
Fixed income securities
Debt Securities, Available-for-sale [Line Items]
Debt securities, Cost Amount	89,625	103,518
Debt securities, Gross Unrealized Gains	642	0
Debt securities, Gross Unrealized (Losses)	0	(1,835)
Debt securities, Fair Value	$ 90,267	$ 101,683

Marketable Securities (Narrativ

Marketable Securities (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Schedule of Investments [Line Items]
Net unrealized gains (losses) of available-for-sale debt securities	$ 494		$ 494		$ (1,413)
Unrealized gains (losses) during the period, income tax expense (benefit)	148		148		(422)
Available-for-sale securities, gross realized gains				$ 1,031
Available-for-sale securities, gross realized losses				1,520
Investments in Affiliated Funds, at fair value	5,533		5,533		4,887
Securities owned	32,862		32,862		30,892
Investment Funds Sponsored by LSV
Schedule of Investments [Line Items]
Investments in Affiliated Funds, at fair value	5,533		5,533		$ 4,887
Gains (losses) from investment funds sponsored by LSV	$ 0	$ 0	$ 646	$ (298)

Line of Credit (Details)

Line of Credit (Details) - USD ($)	Jun. 13, 2016	Sep. 30, 2019
Line of Credit Facility [Line Items]
Letters of credit outstanding amount		$ 11,553,000
Revolving Credit Facility
Line of Credit Facility [Line Items]
Credit facility term of agreement	5 years
Credit facility maximum borrowing capacity	$ 300,000,000
Credit facility stated percentage	0.00%
Credit facility accordion feature, increase limit	$ 100,000,000
Credit facility remaining borrowing capacity		288,447,000
Revolving Credit Facility \| London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Credit facility variable interest rate basis spread	1.00%
Revolving Credit Facility \| Federal Funds Rate
Line of Credit Facility [Line Items]
Credit facility variable interest rate basis spread	0.50%
Revolving Credit Facility \| Minimum
Line of Credit Facility [Line Items]
Credit facility commitment fee per annum on daily unused portion	0.15%
Revolving Credit Facility \| Minimum \| Lender's Base Rate Plus Market Spread
Line of Credit Facility [Line Items]
Credit facility variable interest rate basis spread	0.25%
Revolving Credit Facility \| Minimum \| London Interbank Offered Rate (LIBOR)
Line of Credit Facility [Line Items]
Credit facility variable interest rate basis spread	1.25%
Revolving Credit Facility \| Maximum
Line of Credit Facility [Line Items]
Credit facility commitment fee per annum on daily unused portion	0.30%
Revolving Credit Facility \| Maximum \| Lender's Base Rate Plus Market Spread
Line of Credit Facility [Line Items]
Credit facility variable interest rate basis spread	1.00%
Revolving Credit Facility \| 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		0.175%

Shareholders' Equity (Narrative

Shareholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	May 29, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost		$ 50,330		$ 50,330
Total intrinsic value of options exercised				43,246
Aggregate intrinsic value of options exercisable		$ 197,860		$ 197,860
Market value of Company's common stock (in USD per share)		$ 59.26		$ 59.26
Weighted average exercise price per share (in USD per share)		$ 25.08		$ 25.08
Total options outstanding (in shares)		14,132		14,132
Total options exercisable (in shares)		7,890		7,890
Dividends declared per common share (in USD per share)	$ 0.33	$ 0	$ 0	$ 0.33	$ 0.30
Cash dividends declared				$ 49,984	$ 47,139
Common Stock Buyback
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares purchased and retired (in shares)				4,950
Company purchased, cost				$ 267,184
Remaining stock repurchase authorization amount		$ 198,695		$ 198,695
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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Stockholders' Equity Note [Abstract]
Stock-based compensation expense	$ 5,453	$ 5,878	$ 15,555	$ 16,396
Less: Deferred tax benefit	(1,042)	(1,311)	(2,959)	(3,556)
Stock-based compensation expense, net of tax	$ 4,411	$ 4,567	$ 12,596	$ 12,840

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 1,634,501	$ 1,590,882	$ 1,593,147	$ 1,476,839
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Other comprehensive loss before reclassifications			(3,054)
Amounts reclassified from accumulated other comprehensive loss			274
Net current-period other comprehensive loss	(5,040)	(642)	(2,780)	(8,955)
Ending balance	1,703,307	1,630,510	1,703,307	1,630,510
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			(31,587)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Other comprehensive loss before reclassifications			(4,687)
Amounts reclassified from accumulated other comprehensive loss			0
Net current-period other comprehensive loss			(4,687)
Ending balance	(36,274)		(36,274)
Unrealized Gains (Losses) on Investments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			(1,413)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Other comprehensive loss before reclassifications			1,633
Amounts reclassified from accumulated other comprehensive loss			274
Net current-period other comprehensive loss			1,907
Ending balance	494		494
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(30,740)	(28,221)	(33,000)	(19,908)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Net current-period other comprehensive loss	(5,040)	(642)	(2,780)	(8,955)
Ending balance	$ (35,780)	$ (28,863)	$ (35,780)	$ (28,863)

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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Revenues	$ 416,254	$ 408,682	$ 1,226,660	$ 1,219,110
Expenses	279,380	281,320	829,481	833,686
Operating profit (loss)	136,874	127,362	397,179	385,424
Private Banks
Segment Reporting Information [Line Items]
Revenues	117,250	118,449	351,601	361,739
Expenses	110,788	116,471	329,540	343,515
Operating profit (loss)	6,462	1,978	22,061	18,224
Investment Advisors
Segment Reporting Information [Line Items]
Revenues	103,033	102,550	297,916	301,632
Expenses	51,509	53,287	154,569	158,792
Operating profit (loss)	51,524	49,263	143,347	142,840
Institutional Investors
Segment Reporting Information [Line Items]
Revenues	80,337	83,466	241,559	252,391
Expenses	37,268	40,497	115,383	122,617
Operating profit (loss)	43,069	42,969	126,176	129,774
Investment Managers
Segment Reporting Information [Line Items]
Revenues	112,186	101,275	326,037	295,696
Expenses	71,889	65,296	209,326	191,955
Operating profit (loss)	40,297	35,979	116,711	103,741
Investments In New Businesses
Segment Reporting Information [Line Items]
Revenues	3,448	2,942	9,547	7,652
Expenses	7,926	5,769	20,663	16,807
Operating profit (loss)	$ (4,478)	$ (2,827)	$ (11,116)	$ (9,155)

Business Segment Information (R

Business Segment Information (Reconciliation of Total Operating Profit) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Total operating profit from segments	$ 136,874	$ 127,362	$ 397,179	$ 385,424
Income from operations	120,637	112,420	344,334	339,026
Operating Segments
Segment Reporting Information [Line Items]
Total operating profit from segments	136,874	127,362	397,179	385,424
Corporate
Segment Reporting Information [Line Items]
Corporate overhead expenses	$ (16,237)	$ (14,942)	$ (52,845)	$ (46,398)

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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Capital Expenditures	$ 19,909	$ 17,739	$ 57,336	$ 55,023
Depreciation	7,409	7,255	22,162	21,515
Amortization	12,947	12,405	38,407	36,420
Operating Segments
Segment Reporting Information [Line Items]
Capital Expenditures	19,246	17,279	55,702	53,889
Depreciation	7,089	6,938	21,178	20,610
Amortization	12,890	12,347	38,236	36,247
Operating Segments \| Private Banks
Segment Reporting Information [Line Items]
Capital Expenditures	8,018	7,999	25,240	27,767
Depreciation	3,640	3,427	10,774	10,069
Amortization	7,322	6,943	21,680	20,317
Operating Segments \| Investment Advisors
Segment Reporting Information [Line Items]
Capital Expenditures	4,468	3,927	12,973	12,471
Depreciation	1,162	1,168	3,506	3,378
Amortization	2,609	2,445	7,682	7,203
Operating Segments \| Institutional Investors
Segment Reporting Information [Line Items]
Capital Expenditures	1,070	962	2,990	2,926
Depreciation	393	410	1,212	1,310
Amortization	440	427	1,300	1,281
Operating Segments \| Investment Managers
Segment Reporting Information [Line Items]
Capital Expenditures	5,311	4,104	13,535	9,994
Depreciation	1,793	1,796	5,384	5,411
Amortization	2,334	2,346	7,019	7,036
Operating Segments \| Investments In New Businesses
Segment Reporting Information [Line Items]
Capital Expenditures	379	287	964	731
Depreciation	101	137	302	442
Amortization	185	186	555	410
Corporate
Segment Reporting Information [Line Items]
Capital Expenditures	663	460	1,634	1,134
Depreciation	320	317	984	905
Amortization	$ 57	$ 58	$ 171	$ 173

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Income Tax Contingency [Line Items]
Gross liability for unrecognized tax benefits, exclusive of interest and penalties	$ 14,627	$ 14,367
Unrecognized tax benefits that would affect effective tax rate	14,183	13,774
Interest and penalties on unrecognized benefits	1,520	$ 1,289
Settlement and Lapse of Statute
Income Tax Contingency [Line Items]
Unrecognized tax benefits within the next twelve months	$ 1,008

Income Taxes (Interest And Pena

Income Taxes (Interest And Penalties) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Gross liability for unrecognized tax benefits, exclusive of interest and penalties	$ 14,627	$ 14,367
Interest and penalties on unrecognized benefits	1,520	1,289
Total gross uncertain tax positions	16,147	15,656
Amount included in Current liabilities	1,008	3,131
Amount included in Other long-term liabilities	$ 15,139	$ 12,525

Income Taxes (Effective Income

Income Taxes (Effective Income Tax Rate Reconciliation) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Statutory rate	21.00%	21.00%	21.00%	21.00%
State taxes, net of federal tax benefit	2.60%	2.30%	2.60%	2.30%
Foreign tax expense and tax rate differential	(0.30%)	(0.20%)	(0.20%)	(0.20%)
Tax benefit from stock option exercises	(2.20%)	(1.40%)	(1.50%)	(4.80%)
Expiration of the statute of limitations	(1.20%)	(1.00%)	(0.40%)	(0.30%)
Provision-to-return adjustment	(0.60%)	(2.30%)	(0.20%)	(0.80%)
Other, net	(0.40%)	0.20%	(0.30%)	0.00%
Effective income tax rate	18.90%	18.60%	21.00%	17.20%

Commitments and Contingencies (

Commitments and Contingencies (Details)	Sep. 30, 2019Lawsuit
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

Business Acquisition (Details)

Business Acquisition (Details) - USD ($) $ in Thousands	Apr. 02, 2018	Sep. 30, 2019	Sep. 30, 2018
Business Acquisition [Line Items]
Net cash consideration		$ 0	$ 5,794
Huntington Steele, LLC
Business Acquisition [Line Items]
Total purchase price	$ 17,914
Net cash consideration	5,794
Cash acquired from acquisition	125
Contingent purchase price	$ 12,120
Payment for contingent purchase price		433
Accrued liabilities \| Huntington Steele, LLC
Business Acquisition [Line Items]
Contingent purchase price, current		535
Other long-term liabilities \| Huntington Steele, LLC
Business Acquisition [Line Items]
Contingent purchase price, noncurrent		$ 11,152

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Details) - USD ($)	9 Months Ended
Goodwill and Intangible Assets (Details) - USD ($)	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Apr. 02, 2018	Jul. 03, 2017
Goodwill [Line Items]
Goodwill	$ 64,489,000		$ 64,489,000
Goodwill change during period	0
Amortization expense	$ 2,763,000	$ 2,617,000
Huntington Steele, LLC
Goodwill [Line Items]
Goodwill				$ 11,499,000
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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 416,254	$ 408,682	$ 1,226,660	$ 1,219,110
United States
Disaggregation of Revenue [Line Items]
Revenues	351,609	338,413	1,030,764	1,009,427
United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	37,321	42,464	114,972	127,675
Canada
Disaggregation of Revenue [Line Items]
Revenues	12,728	13,625	37,705	41,547
Ireland
Disaggregation of Revenue [Line Items]
Revenues	14,434	13,855	42,521	38,967
Other
Disaggregation of Revenue [Line Items]
Revenues	162	325	698	1,494
Investment management fees from pooled investment products
Disaggregation of Revenue [Line Items]
Revenues	120,310	123,647	351,927	370,806
Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	96,026	95,760	284,955	283,555
Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	102,977	92,566	298,514	269,089
Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	43,462	45,460	130,529	135,085
Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	36,807	35,342	111,433	110,132
Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	4,931	5,200	14,259	18,682
Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	11,741	10,707	35,043	31,761
Private Banks
Disaggregation of Revenue [Line Items]
Revenues	117,250	118,449	351,601	361,739
Private Banks \| United States
Disaggregation of Revenue [Line Items]
Revenues	76,864	73,188	229,207	226,990
Private Banks \| United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	24,604	28,647	75,649	85,177
Private Banks \| Canada
Disaggregation of Revenue [Line Items]
Revenues	10,985	11,730	32,527	34,847
Private Banks \| Ireland
Disaggregation of Revenue [Line Items]
Revenues	4,797	4,884	14,218	14,725
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	34,074	34,897	100,498	105,251
Private Banks \| Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	314	197	1,299	609
Private Banks \| Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	434	381	1,172	1,138
Private Banks \| Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	43,462	44,836	130,529	133,336
Private Banks \| Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	34,018	32,925	103,502	102,980
Private Banks \| Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	3,533	3,408	9,896	13,022
Private Banks \| Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	1,415	1,805	4,705	5,403
Investment Advisors
Disaggregation of Revenue [Line Items]
Revenues	103,033	102,550	297,916	301,632
Investment Advisors \| United States
Disaggregation of Revenue [Line Items]
Revenues	103,033	102,550	297,916	301,632
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	72,150	73,663	208,860	218,562
Investment Advisors \| Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	26,240	24,525	75,526	70,678
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	4,643	4,362	13,530	12,392
Institutional Investors
Disaggregation of Revenue [Line Items]
Revenues	80,337	83,466	241,559	252,391
Institutional Investors \| United States
Disaggregation of Revenue [Line Items]
Revenues	63,405	64,601	189,383	193,417
Institutional Investors \| United Kingdom
Disaggregation of Revenue [Line Items]
Revenues	12,717	13,817	39,323	42,498
Institutional Investors \| Canada
Disaggregation of Revenue [Line Items]
Revenues	1,743	1,895	5,178	6,700
Institutional Investors \| Ireland
Disaggregation of Revenue [Line Items]
Revenues	2,310	2,828	6,977	8,282
Institutional Investors \| Other
Disaggregation of Revenue [Line Items]
Revenues	162	325	698	1,494
Institutional Investors \| Investment management fees from pooled investment products
Disaggregation of Revenue [Line Items]
Revenues	13,602	14,614	41,062	45,819
Institutional Investors \| Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	66,373	68,318	199,620	205,202
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	362	534	877	1,370
Investment Managers
Disaggregation of Revenue [Line Items]
Revenues	112,186	101,275	326,037	295,696
Investment Managers \| United States
Disaggregation of Revenue [Line Items]
Revenues	104,859	95,132	304,711	279,736
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	7,327	6,143	21,326	15,960
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	161	206	550	445
Investment Managers \| Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	0	79	0	242
Investment Managers \| Investment operations fees
Disaggregation of Revenue [Line Items]
Revenues	102,543	92,185	297,342	267,951
Investment Managers \| Investment processing fees - PaaS
Disaggregation of Revenue [Line Items]
Revenues	0	624	0	1,749
Investment Managers \| Investment processing fees - SaaS
Disaggregation of Revenue [Line Items]
Revenues	2,789	2,417	7,931	7,152
Investment Managers \| Professional services fees
Disaggregation of Revenue [Line Items]
Revenues	1,398	1,792	4,363	5,660
Investment Managers \| Account fees and other
Disaggregation of Revenue [Line Items]
Revenues	5,295	3,972	15,851	12,497
Investments In New Businesses
Disaggregation of Revenue [Line Items]
Revenues	3,448	2,942	9,547	7,652
Investments In New Businesses \| United States
Disaggregation of Revenue [Line Items]
Revenues	3,448	2,942	9,547	7,652
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	323	267	957	729
Investments In New Businesses \| Investment management fees from investment management agreements
Disaggregation of Revenue [Line Items]
Revenues	3,099	2,641	8,510	6,824
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	$ 26	$ 34	$ 80	$ 99

Leases (Narrative) (Details)

Leases (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Leases (Narrative) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Operating leases expense	$ 2,502	$ 7,599

Leases (Schedule of Future Mini

Leases (Schedule of Future Minimum Lease Payments) (Details) $ in Thousands	Sep. 30, 2019USD ($)
Leases [Abstract]
2019 (excluding the nine months ended September 30, 2019)	$ 2,515
2020	8,955
2021	7,657
2022	7,369
2023	7,374
Thereafter	16,726
Total future minimum lease payments	50,596
Less: Imputed interest	(4,892)
Lease liabilities	$ 45,704

Leases (Supplemental Consolidat

Leases (Supplemental Consolidated Balance Sheet Information Related to Operating Leases) (Details) $ in Thousands	Sep. 30, 2019USD ($)
Leases [Abstract]
Current portion of long-term operating lease liabilities	$ 7,888
Long-term Operating Lease Liabilities	37,816
Total operating lease liabilities	$ 45,704
Weighted average remaining lease term	6 years 6 months
Weighted average discount rate	2.66%

Leases (Supplemental Cash Flow

Leases (Supplemental Cash Flow Information Related to Operating Leases) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Leases [Abstract]
Cash paid for amounts included in the measurement of lease liabilities	$ 8,053
Right-of-use assets obtained in exchange for lease obligations	$ 4,178

Uncategorized Items - seic-9301

Label	Element	Value
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 14,402,000
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 14,402,000