Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net income	$ 547,918	$ 582,746
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of deferred sales commissions	26,506	26,678
Non-cash long-term incentive compensation expense	19,109	36,426
Depreciation and other amortization	68,868	44,702
Unrealized losses (gains) on investments	3,892	47,765
Non-cash lease expense	76,745	76,050
Change in estimate of contingent payment arrangements	13,115	0
Other, net	18,102	20,158
Changes in assets and liabilities:
Decrease in securities, segregated	594,497	168,835
Decrease (increase) in receivables	332,161	(224,089)
(Increase) decrease in investments	(24,726)	12,253
(Increase) in deferred sales commissions	(47,442)	(6,214)
(Increase) in other assets	(53,776)	(76,810)
(Decrease) in payables	(1,253,296)	(75,629)
(Decrease) increase in accounts payable and accrued expenses	(2,656)	1,571
Increase in accrued compensation and benefits	366,485	360,817
Cash payments to relieve operating lease liabilities	(80,678)	(82,223)
Net cash provided by operating activities	790,317	1,013,147
Cash flows from investing activities:
Purchases of furniture, equipment and leasehold improvements	(21,399)	(36,088)
Cash Acquired from Acquisition, Net	0	40,282
Net cash (used in) provided by investing activities	(21,399)	4,194
Cash flows from financing activities:
Repayment of debt, net	(90,000)	(65,000)
(Decrease) in overdrafts payable	0	(19,746)
Distributions to General Partner and Unitholders	(630,789)	(862,858)
Capital contributions (to) affiliates	(2,499)	(312)
Additional investments by AB Holding with proceeds from exercise of compensatory options to buy AB Holding Units	0	178
Purchases of AB Holding Units to fund long-term incentive compensation plan awards, net	(70,837)	(107,295)
Repayment of acquisition-related debt obligation	0	(42,661)
Other, net	(3,523)	(1,268)
Net cash used in financing activities	(993,996)	(1,146,307)
Effect of exchange rate changes on cash and cash equivalents	(2,240)	(89,665)
Net (decrease) in cash and cash equivalents	(227,318)	(218,631)
Cash and cash equivalents as of beginning of the period	1,309,017	1,376,026
Cash and cash equivalents as of end of the period	1,081,699	1,157,395
Non-cash investing activities:
Fair value of assets acquired (less cash acquired of $40.8 in 2022)	0	1,050,234
Fair value of deferred tax asset recorded	0	4,823
Fair value of liabilities assumed	0	300,381
Fair value of redeemable non-controlling interest assumed	0	13,191
Non-cash financing activities:
Payables recorded under contingent payment arrangements	0	229,571
Equity consideration issued/to be issued in connection with acquisition	0	552,196
Company-sponsored investment funds
Adjustments to reconcile net income to net cash provided by operating activities:
Unrealized losses (gains) on investments	(22,413)	90,297
Changes in assets and liabilities:
(Increase) decrease in investments	219,144	51,108
(Decrease) in other assets and liabilities of consolidated company-sponsored investment funds, net	(11,238)	(41,294)
Cash flows from financing activities:
(Redemptions) of non-controlling interest in consolidated company-sponsored investment funds, net	$ (196,348)	$ (47,345)