Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net income	$ 788,619	$ 775,457	$ 1,153,734
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of deferred sales commissions	36,817	34,762	34,364
Non-cash long-term incentive compensation expense	180,451	199,390	216,425
Depreciation and other amortization	92,113	66,617	44,985
Non-cash lease expense	101,761	99,861	98,773
(Gain) loss on assets held for sale	(800)	7,400	0
Change is estimate of contingent payment arrangements	14,050	0	0
Other, net	(4,641)	14,604	22,580
Changes in assets and liabilities:
Decrease (increase) in securities, segregated	654,751	(18,474)	249,521
Decrease (increase) in receivables	629,204	35,410	(360,789)
(Increase) in deferred sales commissions	(71,941)	(12,113)	(45,197)
(Decrease) increase in payables	(1,451,280)	110,112	214,139
(Decrease) increase in accounts payable and accrued expenses	(6,992)	(8,424)	35,877
(Decrease) increase in accrued compensation and benefits	(22,848)	(150,285)	50,545
Cash payments to relieve operating lease liabilities	(107,738)	(109,182)	(114,769)
Net cash provided by operating activities	872,292	1,121,231	1,298,782
Cash flows from investing activities:
Purchases of furniture, equipment and leasehold improvements	(33,627)	(62,308)	(61,931)
Acquisition of businesses, net of cash acquired	0	40,282	(3,793)
Net cash used in investing activities	(33,627)	(22,026)	(65,724)
Cash flows from financing activities:
Proceeds from debt, net	164,316	235,000	80,000
(Decrease) increase in overdrafts payable	0	(25,411)	16,192
Distributions to General Partner and Unitholders	(839,271)	(1,069,820)	(1,059,892)
Capital contributions (to) from affiliates	(2,164)	1,590	(2,346)
Additional investments by AB Holding with proceeds from exercise of compensatory options to buy AB Holding Units	0	178	3,402
Purchases of AB Holding Units to fund long-term incentive compensation plan awards, net	(144,086)	(210,568)	(261,825)
Payment of acquisition-related debt obligation	0	(42,661)	0
Other, net	(4,870)	(2,131)	(2,186)
Net cash used in financing activities	(1,009,320)	(1,109,980)	(912,956)
Effect of exchange rate changes on cash and cash equivalents	22,527	(56,234)	(17,982)
Net (decrease) increase in cash and cash equivalents	(148,128)	(67,009)	302,120
Cash and cash equivalents as of beginning of the period	1,309,017	1,376,026	1,073,906
Cash and cash equivalents as of end of the period	1,160,889	1,309,017	1,376,026
Cash paid:
Interest paid	155,335	78,434	5,263
Income taxes paid	57,261	55,473	55,656
Non-cash investing activities:
Fair value of assets acquired (excluding cash acquired of zero, $40.8 million and $2.8 million, for 2023, 2022 and 2021, respectively)	0	1,085,141	13,235
Fair value of deferred tax asset recorded	0	5,072	0
Fair value of liabilities assumed	0	296,750	1,642
Fair value of non-redeemable non-controlling interest recorded	0	13,191	0
Non-cash financing activities:
Payables recorded under contingent payment arrangements	0	231,385	7,800
Equity consideration issued in connection with acquisition	0	589,169	0
Excluding company-sponsored investment funds
Adjustments to reconcile net income to net cash provided by operating activities:
Unrealized (gains) losses on investments	(7,810)	40,857	4,454
Changes in assets and liabilities:
(Increase) in investments	(10,656)	(10,331)	(27,000)
(Increase) in other assets	(36,263)	(5,487)	(6,578)
Company-sponsored investment funds
Adjustments to reconcile net income to net cash provided by operating activities:
Unrealized (gains) losses on investments	(48,350)	73,194	1,882
Changes in assets and liabilities:
(Increase) in investments	167,712	23,295	(312,325)
(Increase) in other assets	(23,867)	(45,432)	38,161
Cash flows from financing activities:
(Redemptions) subscriptions of non-controlling interests of consolidated company-sponsored investment funds, net	$ (183,245)	$ 3,843	$ 313,699