Business Description and Organization (Details) - AllianceBernstein Corporation	12 Months Ended
	Dec. 31, 2018
Ownership structure of AB Holding
Limited partners or members ownership interest in Company (percent)	100.00%
EQH and its subsidiaries
Ownership structure of AB Holding
Limited partners or members ownership interest in Company (percent)	63.60%
AB Holding
Ownership structure of AB Holding
Limited partners or members ownership interest in Company (percent)	35.60%
Unaffiliated holders
Ownership structure of AB Holding
Limited partners or members ownership interest in Company (percent)	0.80%