Business Description Organization and Basis of Presentation (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2015 USD ($) shares	Sep. 30, 2015 USD ($) shares
Ownership structure of AllianceBernstein expressed as a percentage of general and limited partnership interests [Abstract]
AXA and its subsidiaries ownership interest in holding company (percent)	1.50%	1.50%
Limited partners or members ownership interest in company (percent)		100.00%
General partnership information [Abstract]
Threshold amount for including institutions in private clients (less than $25 million) | $	$ 25	$ 25
General Partnership number of general partnership units owned in Holding Company (in units)	100,000	100,000
General partnership interest in Company	1.00%	1.00%
AXA and its subsidiaries economic interest in Company (percent)		63.40%
AXA and its subsidiaries
Ownership structure of AllianceBernstein expressed as a percentage of general and limited partnership interests [Abstract]
Limited partners or members ownership interest in company (percent)		62.80%
AB Holding
Ownership structure of AllianceBernstein expressed as a percentage of general and limited partnership interests [Abstract]
Limited partners or members ownership interest in company (percent)		35.80%
Unaffiliated holders
Ownership structure of AllianceBernstein expressed as a percentage of general and limited partnership interests [Abstract]
Limited partners or members ownership interest in company (percent)		1.40%