Business Description, Organization and Basis of Presentation (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Ownership structure of AllianceBernstein expressed as a percentage of general and limited partnership interests [Abstract]
AXA and its subsidiaries ownership interest in holding company (in hundredths)	1.40%
Limited partners or members ownership interest in company (in hundredths)	100.00%
General partnership information [Abstract]
General Partnership number of general partnership units owned in Holding Company (in units)	100,000
General partnership interest in Company (in hundredths)	1.00%
AXA and its subsidiaries economic interest in Company (in hundredths)	64.20%
Impact of revision on cash flows		$ 0.9
AXA And Its Subsidiaries [Member]
Ownership structure of AllianceBernstein expressed as a percentage of general and limited partnership interests [Abstract]
Limited partners or members ownership interest in company (in hundredths)	61.00%
Holdings [Member]
Ownership structure of AllianceBernstein expressed as a percentage of general and limited partnership interests [Abstract]
Limited partners or members ownership interest in company (in hundredths)	37.60%
Unaffiliated Holders [Member]
Ownership structure of AllianceBernstein expressed as a percentage of general and limited partnership interests [Abstract]
Limited partners or members ownership interest in company (in hundredths)	1.40%