Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
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)	39.30%	36.10%	39.30%	36.10%
Equity in net income attributable to AB Unitholders	$ 69,121	$ 75,358	$ 145,503	$ 169,711
Computation of income tax [Abstract]
AB qualifying revenues	$ 670,328	$ 665,807	$ 1,370,543	$ 1,410,524
Multiplied by: weighted average equity ownership interest for calculating tax (percent)	35.70%	30.60%	35.70%	31.00%
Multiplied by: federal tax (percent)	3.50%	3.50%	3.50%	3.50%
Federal income taxes	$ 8,371	$ 7,120	$ 17,120	$ 15,306
State income taxes	192	97	388	336
Total income taxes	$ 8,563	$ 7,217	$ 17,508	$ 15,642
Effective tax rate (percent)	12.40%	9.60%	12.00%	9.20%
Changes in components for calculation of income tax [Abstract]
Change in net income attributable to AB Unitholders (percent)	(15.80%)		(21.20%)
Change in equity in net income attributable to AB Unitholders (percent)	(8.30%)		(14.30%)
Change in AB qualifying revenues (percent)	0.70%		(2.80%)
Change in income taxes (percent)	18.70%		11.90%
Variable Interest Entity, Primary Beneficiary
Income Tax Contingency [Line Items]
Net income attributable to AB Unitholders	$ 175,737	$ 208,769	$ 369,888	$ 469,496