Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Cash flows from operating activities:
Net income	$ 539,707	$ 382,678
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of deferred sales commissions	25,147	16,921
Non-cash long-term incentive compensation expense	20,885	15,367
Depreciation and other amortization	46,319	45,928
Non-cash lease expense	57,705	51,768
Other, net	15,017	4,699
Changes in assets and liabilities:
Decrease in securities, segregated	276,098	643,417
Decrease in receivables	33,358	336,744
(Increase) in deferred sales commissions	(62,552)	(29,916)
(Decrease) in payables	(269,927)	(1,027,887)
Increase (decrease) in accounts payable and accrued expenses	64,332	(15,595)
Increase in accrued compensation and benefits	212,993	185,443
Cash payments to relieve operating lease liabilities	(34,911)	(53,498)
Net cash provided by operating activities	945,908	722,321
Cash flows from investing activities:
Purchases of furniture, equipment and leasehold improvements	(56,565)	(14,941)
Divestiture of business (includes $304.0 million in cash proceeds)	(40,196)	0
Capital contribution to equity method investments	(39,401)	0
Proceeds from Equity Method Investment, Distribution, Return of Capital	86,200	0
Net cash contribution (to) affiliates	(752)	(2,030)
Net cash (used in) investing activities	(50,714)	(16,971)
Cash flows from financing activities:
(Repayment of) debt, net	(534,316)	(120,000)
(Decrease) in overdrafts payable	(2)	0
Distributions to General Partner and Unitholders	(481,109)	(435,213)
Purchases of AB Holding Units to fund long-term incentive compensation plan awards, net	(33,789)	(18,662)
Other, net	(5,603)	(2,426)
Net cash (used in) financing activities	(1,168,192)	(772,184)
Effect of exchange rate changes on cash and cash equivalents	(12,665)	16,178
Net (decrease) in cash and cash equivalents	(285,663)	(50,656)
Cash and cash equivalents as of beginning of the period	1,160,889	1,309,017
Cash and cash equivalents as of end of the period	875,226	1,258,361
Excluding Company-Sponsored Investment Funds
Adjustments to reconcile net income to net cash provided by operating activities:
Unrealized (gains) on investments	(5,944)	(1,853)
Equity in earnings of equity method investments	(27,893)	0
(Gain) on divestiture	(134,555)	0
Changes in assets and liabilities:
Decrease in investments	27,092	3,155
(Increase) in other assets	(47,392)	(18,581)
Company-Sponsored Investment Funds
Adjustments to reconcile net income to net cash provided by operating activities:
Unrealized (gains) on investments	(11,527)	(27,027)
Changes in assets and liabilities:
Decrease in investments	155,631	221,636
Increase (decrease) in other assets and liabilities of consolidated company-sponsored investment funds, net	10,539	(11,078)
Cash flows from financing activities:
(Redemptions) of non-controlling interest in consolidated company-sponsored investment funds, net	$ (113,373)	$ (195,883)