Condensed Statements of Income (unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Condensed Statements of Income (unaudited) [Abstract]
Equity in net (loss) income attributable to AllianceBernstein Unitholders	$ (16,595)	$ 34,074	$ 43,915	$ 127,877
Income taxes	6,547	7,071	19,019	21,682
Net (loss) income	$ (23,142)	$ 27,003	$ 24,896	$ 106,195
Net (loss) income per unit:
Basic (in dollars per share)	$ (0.23)	$ 0.26	$ 0.25	$ 1.02
Diluted (in dollars per share)	$ (0.23)	$ 0.26	$ 0.25	$ 1.02