Business Segment Information - Net Revenues Derived From Investment Management, Research and Related Services (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Financial Services Revenue [Abstract]
Total revenues									$ 3,024,048	$ 3,007,792	$ 2,917,971
Less: Interest expense									3,321	2,426	2,924
Net revenues	$ 726,726	$ 738,693	$ 792,737	$ 762,571	$ 787,352	$ 749,748	$ 753,648	$ 714,618	3,020,727	3,005,366	2,915,047
Institutions [Member]
Financial Services Revenue [Abstract]
Total revenues									435,205	434,081	438,946
Retail [Member]
Financial Services Revenue [Abstract]
Total revenues									1,362,541	1,397,135	1,376,370
Private Wealth Management [Member]
Financial Services Revenue [Abstract]
Total revenues									689,853	664,324	591,358
Bernstein Research Services [Member]
Financial Services Revenue [Abstract]
Total revenues									493,463	482,538	445,083
Other Services [Member]
Financial Services Revenue [Abstract]
Total revenues									$ 42,986	$ 29,714	$ 66,214