Net Income Per Unit (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Limited Partners interest in Company (as a percent)	99.00%
Net income per unit, basic and diluted [Abstract]
Net income attributable to AB Unitholders	$ 982,489	$ 1,173,247	$ 764,610
Weighted average units outstanding—basic (in shares)	292,063	286,618	285,125
Weighted average limited partnership Units outstanding – diluted (in shares)	292,063	286,618	285,125
Basic net income per AB Unit (in dollars per share)	$ 3.33	$ 4.05	$ 2.65
Diluted net income per AB Unit (in dollars per unit)	$ 3.33	$ 4.05	$ 2.65
AB Holding | AB
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
General partnership interest in company (percent)	1.00%