Condensed Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 163,178	$ 142,744
Other comprehensive income (loss):
Foreign currency translation adjustments	5,225	(12,275)
Income tax expense	0	0
Foreign currency translation adjustments, net of tax	5,225	(12,275)
Unrealized (losses) gains on investments:
Unrealized (losses) gains arising during period	(8)	189
Less: reclassification adjustment for losses included in net income	(3)	0
Change in unrealized (losses) gains on investments	(5)	189
Income tax (expense) benefit	(1)	119
Unrealized (losses) gains on investments, net of tax	(6)	308
Changes in employee benefit related items:
Amortization of prior service cost	71	0
Recognized actuarial (loss) gain	(433)	237
Changes in employee benefit related items	(362)	237
Income tax expense	(71)	(62)
Employee benefit related items, net of tax	(433)	175
Other comprehensive income (loss)	4,786	(11,792)
Less: Comprehensive (loss) income in consolidated entities attributable to non-controlling interests	(5,697)	1,208
Comprehensive income attributable to AB Unitholders	$ 173,661	$ 129,744