Related Party Transactions - Revenues for Services Provided (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Related Party Transaction [Line Items]
Investment advisory and services fees	$ 1,933,471	$ 1,973,837	$ 1,958,250
Distribution revenues	384,405	427,156	444,970
Other revenues	110,096	101,169	108,788
Bernstein research services	479,875	493,463	482,538
Mutual Funds [Member]
Related Party Transaction [Line Items]
Investment advisory and services fees	998,892	1,056,227	1,061,677
Distribution revenues	371,604	415,380	433,063
Shareholder servicing fees	76,201	85,207	91,020
Other revenues	6,253	4,939	6,694
Bernstein research services	$ 5	$ 4	$ 13