Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 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%	36.20%
Equity in net income attributable to AB Unitholders	$ 76,382	$ 94,353
Computation of income tax [Abstract]
AB qualifying revenues	$ 700,215	$ 744,717
Multiplied by: weighted average equity ownership interest for calculating tax (percent)	35.70%	31.40%
Multiplied by: federal tax (percent)	3.50%	3.50%
Federal income taxes	$ 8,749	$ 8,186
State income taxes	196	239
Total income taxes	$ 8,945	$ 8,425
Effective tax rate (percent)	11.70%	8.90%
Changes in components for calculation of income tax [Abstract]
Change in net income attributable to AB Unitholders (percent)	(25.50%)
Change in equity in net income attributable to AB Unitholders (percent)	(19.00%)
Change in AB qualifying revenues (percent)	(6.00%)
Change in income taxes (percent)	6.20%
Variable Interest Entity, Primary Beneficiary
Income Tax Contingency [Line Items]
Net income attributable to AB Unitholders	$ 194,151	$ 260,727