Business Description Organization and Basis of Presentation (Revision) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Income taxes	$ 10,057	$ 12,506
Net income attributable to AB Unitholders	$ 139,937	$ 166,284
Basic net income per AB Unit (in dollars per unit)	$ 0.52	$ 0.61
Diluted net income per AB Unit (in dollars per unit)	$ 0.51	$ 0.60
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Income taxes		$ 9,864
Net income attributable to AB Unitholders		$ 168,926
Basic net income per AB Unit (in dollars per unit)		$ 0.62
Diluted net income per AB Unit (in dollars per unit)		$ 0.61
Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Income taxes		$ 2,642
Net income attributable to AB Unitholders		$ (2,642)
Basic net income per AB Unit (in dollars per unit)		$ (0.01)
Diluted net income per AB Unit (in dollars per unit)		$ (0.01)