Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2010		Sep. 30, 2010		Jun. 30, 2010		Mar. 31, 2010		Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Statements of Income [Abstract]
Equity in net (loss) income attributable to AllianceBernstein Unitholders	$ (193,458)		$ 34,074		$ 42,745		$ 51,058		$ 50,168		$ 18,914		$ 38,925		$ 54,210		$ (65,581)	$ 162,217	$ 192,513
Income taxes																	27,687	28,059	25,324
Net (loss) income	$ (199,463)		$ 27,003		$ 35,512		$ 43,680		$ 42,925		$ 12,215		$ 31,772		$ 47,246		$ (93,268)	$ 134,158	$ 167,189
Net (loss) income per unit:
Basic (in dollars per share)	$ (1.97)	[1]	$ 0.26	[1]	$ 0.34	[1]	$ 0.42	[1]	$ 0.43	[1]	$ 0.12	[1]	$ 0.31	[1]	$ 0.47	[1]	$ (0.90)	$ 1.33	$ 1.80
Diluted (in dollars per share)	$ (1.97)	[1]	$ 0.26	[1]	$ 0.34	[1]	$ 0.42	[1]	$ 0.42	[1]	$ 0.12	[1]	$ 0.31	[1]	$ 0.46	[1]	$ (0.90)	$ 1.32	$ 1.80

[1] Basic and diluted net income per unit are computed independently for each of the periods presented. Accordingly, the sum of the quarterly net income per unit amounts may not agree to the total for the year.