Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 235,682	$ 243,839
Other comprehensive (loss):
Foreign currency translation adjustments, before tax	(11,822)	(7,138)
Income tax benefit	101	22
Foreign currency translation adjustments, net of tax	(11,721)	(7,116)
Changes in employee benefit related items:
Amortization of prior service cost	6	6
Recognized actuarial gain	323	81
Changes in employee benefit related items	329	87
Income tax (expense)	(9)	0
Employee benefit related items, net of tax	320	87
Other comprehensive (loss)	(11,401)	(7,029)
Less: Comprehensive (loss) in consolidated entities attributable to non-controlling interests	(25,045)	(292)
Comprehensive income attributable to AB Unitholders	$ 249,326	$ 237,102