Business Description, Organization and Basis of Presentation - Summary of Ownership Structure (Details) - AB	6 Months Ended
	Jun. 30, 2025
Ownership structure of AllianceBernstein expressed as a percentage of general and limited partnership interests [Abstract]
Limited partners or members ownership interest in company (percent)	100.00%
EQH 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)	61.90%
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)	37.50%
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)	0.60%