Consolidated Balance Sheets (unaudited) - USD ($)	Mar. 31, 2026	Dec. 31, 2025
Current Assets:
Cash and cash equivalents	$ 363,149,000	$ 399,804,000
Receivables from investment products	55,126,000	63,317,000
Receivables, net of allowance for doubtful accounts of $1,759 and $1,916	710,083,000	709,748,000
Securities owned	32,093,000	33,777,000
Other current assets	73,107,000	66,691,000
Total Current Assets	1,233,558,000	1,273,337,000
Property and Equipment, net of accumulated depreciation of $474,613 and $468,700	149,415,000	150,434,000
Operating Lease Right-of-Use Assets	34,669,000	26,447,000
Capitalized Software, net of accumulated amortization of $678,968 and $669,896	230,746,000	234,272,000
Investments	331,371,000	428,004,000
Goodwill	388,380,000	354,989,000
Intangible Assets, net of accumulated amortization of $58,480 and $49,534	479,517,000	368,272,000
Deferred Contract Costs	56,593,000	53,345,000
Deferred Income Taxes	8,218,000	8,048,000
Deposits Related to Acquisitions	64,839,000	118,606,000
Other Assets, net	83,027,000	60,096,000
Current Liabilities:
Accounts payable	6,685,000	5,404,000
Accrued liabilities	237,722,000	359,823,000
Current portion of long-term operating lease liabilities	10,054,000	8,677,000
Deferred revenue	18,360,000	13,307,000
Total Current Liabilities	272,821,000	387,211,000
Long-term Debt	32,415,000	0
Deferred Income Taxes	14,580,000	16,842,000
Long-term Operating Lease Liabilities	27,016,000	19,885,000
Other Long-term Liabilities	35,195,000	23,626,000
Commitments and Contingencies
Redeemable Non-controlling Interests	269,901,000	243,959,000
Shareholders' Equity:
Common stock, $0.01 par value, 750,000,000 shares authorized; 120,385,568 and 122,232,251 shares issued and outstanding	1,204,000	1,222,000
Capital in excess of par value	1,696,702,000	1,678,787,000
Retained earnings	781,778,000	792,280,000
Accumulated other comprehensive loss, net	(29,430,000)	(24,505,000)
Total SEI Shareholders' Equity	2,450,254,000	2,447,784,000
Non-controlling interests	36,530,000	12,033,000
Total Equity	2,486,784,000	2,459,817,000
Total Liabilities, Redeemable Non-controlling Interests and Equity	3,275,254,000	3,259,844,000
Consolidated VIEs
Current Assets:
Cash and cash equivalents	440,241,000	470,595,000
Assets of Consolidated Variable Interest Entities	214,921,000	183,994,000
Total Assets	214,921,000	183,994,000
Current Liabilities:
Liabilities of Consolidated Variable Interest Entities	136,542,000	108,504,000
Total Liabilities	136,542,000	108,504,000
Consolidated Entity, Excluding Consolidated VIE
Current Assets:
Assets of Consolidated Variable Interest Entities	3,275,254,000	3,259,844,000
Total Assets	3,275,254,000	3,259,844,000
Current Liabilities:
Liabilities of Consolidated Variable Interest Entities	518,569,000	556,068,000
Total Liabilities	$ 518,569,000	$ 556,068,000

Deposits on Future Acquisitions

No definition available.

Name:	seic_DepositsOnFutureAcquisitions
Namespace Prefix:	seic_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).