Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Tax Disclosure [Abstract]
New York City unincorporated business tax (percent)			4.00%
Federal tax rate on partnership gross income (percent)			3.50%
Income Tax Contingency [Line Items]
Multiplied by: weighted average equity ownership interest (percent)	36.50%	36.20%	36.20%	36.40%
Equity in net income attributable to AB Unitholders	$ 63,905	$ 95,921	$ 233,616	$ 282,235
Computation of income tax [Abstract]
AB qualifying revenues	$ 678,682	$ 669,232	$ 2,089,206	$ 1,956,095
Multiplied by: weighted average equity ownership interest for calculating tax (percent)	31.30%	30.20%	31.10%	30.60%
Multiplied by: federal tax (percent)	3.50%	3.50%	3.50%	3.50%
Federal income taxes	$ 7,442	$ 7,073	$ 22,748	$ 20,977
State income taxes	147	172	483	578
Total income taxes	$ 7,589	$ 7,245	$ 23,231	$ 21,555
Effective tax rate (percent)	11.90%	7.60%	9.90%	7.60%
Changes in components for calculation of income tax [Abstract]
Change in net income attributable to AB Unitholders (percent)	(33.80%)		(17.00%)
Change in equity in net income attributable to AB Unitholders (percent)	(33.40%)		(17.20%)
Change in AB qualifying revenues (percent)	1.40%		6.80%
Change in income taxes (percent)	4.70%		7.80%
Variable Interest Entity, Primary Beneficiary
Income Tax Contingency [Line Items]
Net income attributable to AB Unitholders	$ 175,180	$ 264,695	$ 644,676	$ 776,396