Consolidated Balance Sheets (unaudited) - USD ($)	Sep. 30, 2026	Dec. 31, 2025
Current Assets:
Cash and cash equivalents	$ 399,766,000	$ 399,804,000
Receivables from investment products	59,278,000	63,317,000
Receivables, net of allowance for doubtful accounts of $2,398 and $1,916	851,279,000	709,748,000
Securities owned	25,750,000	33,777,000
Other current assets	75,611,000	66,691,000
Total Current Assets	1,411,684,000	1,273,337,000
Property and Equipment, net of accumulated depreciation of $487,903 and $468,700	153,496,000	150,434,000
Operating Lease Right-of-Use Assets	30,186,000	26,447,000
Capitalized Software, net of accumulated amortization of $697,165 and $669,896	224,189,000	234,272,000
Investments	335,895,000	428,004,000
Goodwill	392,205,000	354,989,000
Intangible assets, net of accumulated Amortization	481,727,000	368,272,000
Deferred Contract Costs	58,954,000	53,345,000
Deferred Income Taxes	9,178,000	8,048,000
Deposits Related to Acquisitions	33,005,000	118,606,000
Other Assets, net	80,335,000	60,096,000
Current Liabilities:
Accounts payable	13,905,000	5,404,000
Accrued liabilities	284,920,000	359,823,000
Current portion of long-term debt	5,754,000	0
Current portion of long-term operating lease liabilities	9,124,000	8,677,000
Deferred revenue	13,648,000	13,307,000
Total Current Liabilities	327,351,000	387,211,000
Long-term Debt	30,951,000	0
Deferred Income Taxes	14,206,000	16,842,000
Long-term Operating Lease Liabilities	23,474,000	19,885,000
Other Long-term Liabilities	24,823,000	23,626,000
Commitments and Contingencies
Redeemable Non-controlling Interests	323,105,000	243,959,000
Shareholders' Equity:
Common stock, $0.01 par value, 750,000,000 shares authorized; 118,942,181 and 122,232,251 shares issued and outstanding	1,189,000	1,222,000
Capital in excess of par value	1,758,970,000	1,678,787,000
Retained earnings	785,633,000	792,280,000
Accumulated other comprehensive loss, net	(33,229,000)	(24,505,000)
Total SEI Shareholders' Equity	2,512,563,000	2,447,784,000
Non-controlling interests	41,630,000	12,033,000
Total Equity	2,554,193,000	2,459,817,000
Total Liabilities, Redeemable Non-controlling Interests and Equity	3,434,639,000	3,259,844,000
Consolidated VIEs
Current Assets:
Cash and cash equivalents	485,223,000	470,595,000
Assets of Consolidated Variable Interest Entities	223,785,000	183,994,000
Total Assets	223,785,000	183,994,000
Current Liabilities:
Liabilities of Consolidated Variable Interest Entities	136,536,000	108,504,000
Total Liabilities	136,536,000	108,504,000
Consolidated Entity, Excluding Consolidated VIE
Current Assets:
Assets of Consolidated Variable Interest Entities	3,434,639,000	3,259,844,000
Total Assets	3,434,639,000	3,259,844,000
Current Liabilities:
Liabilities of Consolidated Variable Interest Entities	557,341,000	556,068,000
Total Liabilities	$ 557,341,000	$ 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).