Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net income	$ 575,067	$ 525,195
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of deferred sales commissions	19,582	10,348
Non-cash long-term incentive compensation expense	23,594	36,737
Depreciation and other amortization	107,910	125,729
Unrealized losses (gains) on investments	20,593	(17,386)
Other, net	(1,072)	3,652
Changes in assets and liabilities:
(Increase) decrease in securities, segregated	(774,447)	211,405
(Increase) decrease in receivables	(1,555)	214,522
(Increase) decrease in investments	(8,037)	407,616
(Increase) in deferred sales commissions	(46,681)	(20,559)
Decrease (increase) in right-of-use assets	1,845	(8,336)
Increase in other assets	40,130	20,361
Increase (decrease) in payables	982,957	(733,097)
(Decrease) in lease liabilities	(71,431)	(83,161)
(Decrease) in accounts payable and accrued expenses	(5,988)	(39,225)
Increase in accrued compensation and benefits	361,251	334,900
Net cash provided by operating activities	1,581,504	806,018
Cash flows from investing activities:
Purchases of furniture, equipment and leasehold improvements	(12,357)	(24,311)
Acquisition of businesses, net of cash acquired	(13,552)	5,255
Net cash used in investing activities	(25,909)	(19,056)
Cash flows from financing activities:
(Repayment) of commercial paper, net	0	(227,528)
(Repayment) of EQH Facility	(260,000)	0
Borrowings of bank loans	0	55,000
Increase (decrease) in overdrafts payable	2,640	(72,878)
Distributions to General Partner and Unitholders	(630,882)	(514,299)
Capital contributions (to) from affiliates	(865)
Capital contributions (to) from affiliates		470
Additional investments by AB Holding with proceeds from exercise of compensatory options to buy AB Holding Units	147	9,642
Purchases of AB Holding Units to fund long-term incentive compensation plan awards, net	(53,458)	(81,790)
Other	1,276	(2,460)
Net cash (used in) financing activities	(1,205,163)	(710,166)
Effect of exchange rate changes on cash and cash equivalents	1,415	(8,090)
Net increase in cash and cash equivalents	351,847	68,706
Cash and cash equivalents as of beginning of the period	691,171	653,324
Cash and cash equivalents as of end of the period	1,043,018	722,030
Non-cash investing activities:
Fair value of assets acquired (excluding cash acquired of $0.6 million and $11.8 million, respectively)	18,389	28,966
Fair value of liabilities assumed	437	16,837
Non-cash financing activities:
Payables recorded under contingent payment arrangements	4,400	17,384
Company-sponsored investment funds
Adjustments to reconcile net income to net cash provided by operating activities:
Unrealized losses (gains) on investments	8,254	(29,522)
Changes in assets and liabilities:
(Increase) decrease in investments	344,574	(155,064)
Increase in other assets	4,958	1,903
Cash flows from financing activities:
(Redemptions) subscriptions of non-controlling interest in consolidated company-sponsored investment funds, net	$ (264,021)	$ 123,677