Net Income Per Unit (Details) (USD $) In Thousands, except Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Net Income Per Unit [Abstract]
Net income - basic	$ 35,512	$ 31,772	$ 79,192	$ 79,018
Additional allocation of equity in net income attributable to AllianceBernstein resulting from assumed dilutive effect of compensatory options	141	484	379	1,109
Net income - diluted	$ 35,653	$ 32,256	$ 79,571	$ 80,127
Weighted average units outstanding - basic (in units)	103,969	101,442	104,339	101,409
Dilutive effect of compensatory options (in units)	556	2,026	682	1,933
Weighted average units outstanding - diluted (in units)	104,525	103,468	105,021	103,342
Basic net income per unit (in dollars per unit)	$ 0.34	$ 0.31	$ 0.76	$ 0.78
Diluted net income per unit (in dollars per unit)	$ 0.34	$ 0.31	$ 0.76	$ 0.78
Out-of-the-money options from the diluted net income per unit (in units)	4,408,829	5,048,345	4,408,829	5,048,345