Consolidated Company-Sponsored Investment Funds - Schedule of Balances of Consolidated VIEs and VOEs included in Statement of Financial Condition (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023
Condensed Balance Sheet Statements, Captions [Line Items]
Total assets	$ 8,932,174	$ 9,609,806
Liabilities	4,216,823	4,947,024
Redeemable non-controlling interest	127,217	209,420
Partners' capital attributable to AB Unitholders	4,588,134	4,453,362	$ 4,324,531
Total liabilities, redeemable non-controlling interest and partners' capital	8,932,174	9,609,806
Company-Sponsored Investment Funds
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	5,813	7,739
Investments	267,029	397,174
Other assets	4,735	25,299
Total assets	277,577	430,212
Liabilities	4,933	12,537
Redeemable non-controlling interest	127,217	209,420
Partners' capital attributable to AB Unitholders	145,427	208,255
Total liabilities, redeemable non-controlling interest and partners' capital	277,577	430,212
VIEs
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	5,765	7,572
Investments	211,994	286,619
Other assets	3,041	15,010
Total assets	220,800	309,201
Liabilities	3,631	9,699
Redeemable non-controlling interest	120,840	202,882
Partners' capital attributable to AB Unitholders	96,329	96,620
Total liabilities, redeemable non-controlling interest and partners' capital	220,800	309,201
VOEs
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	48	167
Investments	55,035	110,555
Other assets	1,694	10,289
Total assets	56,777	121,011
Liabilities	1,302	2,838
Redeemable non-controlling interest	6,377	6,538
Partners' capital attributable to AB Unitholders	49,098	111,635
Total liabilities, redeemable non-controlling interest and partners' capital	$ 56,777	$ 121,011