Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 988,875	$ 1,193,485	$ 788,619
Other comprehensive income:
Foreign currency translation adjustments, before reclassification and tax	30,334	(20,843)	14,262
Less: reclassification adjustment for (losses) included in net income upon liquidation	0	(10,197)	(389)
Foreign currency translation adjustments, before tax	30,334	(10,646)	14,651
Income tax (expense) benefit	(453)	59	(618)
Foreign currency translation adjustments, net of tax	29,881	(10,587)	14,033
Changes in employee benefit related items:
Amortization of prior service cost	611	24	24
Recognized actuarial gain	0	1,504	9,135
Less: reclassification adjustment for (losses) included in net income upon retirement plan liquidation	(22,830)	(4,931)	0
Changes in employee benefit related items	23,441	6,459	9,159
Income tax (expense)	(130)	(89)	(79)
Employee benefit related items, net of tax	23,311	6,370	9,080
Other comprehensive income (loss)	53,192	(4,217)	23,113
Less: Comprehensive income in consolidated entities attributable to non-controlling interests	6,386	20,238	24,009
Comprehensive income attributable to AB Unitholders	$ 1,035,681	$ 1,169,030	$ 787,723