Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Tax Disclosure [Abstract]
New York City unincorporated business tax (percent)	4.00%
Federal tax rate on partnership gross income (percent)	3.50%
Computation of equity in net income attributable to AllianceBernstein Unitholders [Abstract]
Net income attributable to AB Unitholders	$ 139,937	$ 166,284
Multiplied by: weighted average equity ownership interest (percent)	35.50%	36.20%
Equity in net income attributable to AB Unitholders	$ 49,666	$ 60,177
Computation of income tax [Abstract]
AB qualifying revenues	$ 546,177	$ 513,873
Multiplied by: weighted average equity ownership interest for calculating tax (percent)	29.60%	30.60%
Multiplied by: federal tax (percent)	3.50%	3.50%
Federal income taxes	$ 5,651	$ 5,502
State income taxes	105	83
Total income taxes	$ 5,756	$ 5,585
Effective tax rate (percent)	11.60%	9.30%
Changes in components for calculation of income tax [Abstract]
Change in net income attributable to AllianceBernstein Unitholders (percent)	(15.80%)
Change in equity in net income attributable to AllianceBernstein Unitholders (percent)	(17.50%)
Change in AllianceBernstein qualifying revenues (percent)	6.30%
Change in income taxes (percent)	3.10%