Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income	$ 781,683	$ 779,498	$ 720,800
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of deferred sales commissions	15,029	21,343	31,886
Non-cash long-term incentive compensation expense	208,182	187,514	185,234
Depreciation and other amortization	166,542	70,000	66,999
Unrealized (gains) losses on investments	(13,431)	23,164	3,554
Other, net	10,281	(6,446)	13,189
Changes in assets and liabilities:
Decrease (increase) in securities, segregated	74,688	(353,204)	129,747
Decrease (increase) in receivables	223,137	(207,000)	67,539
Decrease (increase) in investments	460,347	(294,383)	293
(Increase) decrease in deferred sales commissions	(34,177)	(8,365)	1,878
(Increase) in right-of-use assets	(11,141)
(Increase) in other assets	(23,140)	(152,726)	(2,255)
(Decrease) increase in payables	(641,369)	1,024,317	(338,523)
(Decrease) in lease liabilities	(107,276)
(Decrease) increase in accounts payable and accrued expenses	(56,518)	(11,225)	10,657
(Decrease) increase in accrued compensation and benefits	(7,486)	4,341	12,187
Net cash provided by operating activities	827,480	1,308,481	645,452
Cash flows from investing activities:
Purchases of investments	0	0	(12)
Proceeds from sales of investments	0	0	11
Purchases of furniture, equipment and leasehold improvements	(28,303)	(32,789)	(39,417)
Proceeds from sales of furniture, equipment and leasehold improvements	0	0	75
Acquisition of businesses, net of cash acquired	5,255	0	0
Net cash used in investing activities	(23,048)	(32,789)	(39,343)
Cash flows from financing activities:
(Repayment) issuance of commercial paper, net	(532,895)	24,546	(28,553)
Proceeds from EQH facility	560,000	0	0
Repayment from bank loans	(25,000)	(50,000)
Proceeds from bank loans			75,000
(Decrease) increase in overdrafts payable	(59,924)	3,273	63,393
Distributions to General Partner and Unitholders	(703,512)	(858,193)	(644,139)
Purchases (redemptions) of non-controlling interests of consolidated company-sponsored investment funds, net	0	(638)	(43,217)
Capital contributions from affiliates	269		366
Capital contributions to affiliates		(1,421)
Payments of contingent payment arrangements/purchase of shares	(1,991)	(1,093)	(7,592)
Additional investments by AB Holding with proceeds from exercise of compensatory options to buy AB Holding Units	11,511	16,589	20,110
Purchases of AB Holding Units to fund long-term incentive compensation plan awards, net	(171,930)	(267,427)	(219,627)
Other	(1,580)	(2,151)	(2,836)
Net cash used in financing activities	(774,961)	(1,608,658)	(623,931)
Effect of exchange rate changes on cash and cash equivalents	8,376	(12,158)	21,760
Net increase (decrease) in cash and cash equivalents	37,847	(345,124)	3,938
Cash and cash equivalents as of beginning of the period	653,324	998,448	994,510
Cash and cash equivalents as of end of the period	691,171	653,324	998,448
Cash paid:
Interest paid	66,002	60,286	30,975
Income taxes paid	52,444	41,946	67,421
Non-cash investing activities:
Fair value of assets acquired (excluding cash acquired of $11.8 million)	28,966	0	0
Fair value of liabilities assumed	16,837	0	0
Non-cash financing activities:
Payables recorded under contingent payment arrangements	17,384	0	0
Consolidated Company-Sponsored Investment Funds
Adjustments to reconcile net income to net cash provided by operating activities:
Unrealized (gains) losses on investments	(36,150)	(14,217)	(36,340)
Changes in assets and liabilities:
Decrease (increase) in investments	(193,158)	908,804	(639,067)
(Increase) in other assets	11,437	(662,934)	417,674
Cash flows from financing activities:
Purchases (redemptions) of non-controlling interests of consolidated company-sponsored investment funds, net	$ 150,091	$ (472,143)	$ 163,164