Condensed Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 131,987	$ 155,769	$ 295,165	$ 298,513
Other comprehensive (loss) income
Foreign currency translation adjustment, before reclassification and tax:	(5,123)	7,598	102	(4,677)
Less: reclassification adjustment for gains included in net income upon liquidation	0	1,542	0	1,542
Foreign currency translation adjustments, before tax	(5,123)	6,056	102	(6,219)
Income tax expense	0	0	0	0
Foreign currency translation adjustments, net of tax	(5,123)	6,056	102	(6,219)
Unrealized (losses) on investments:
Unrealized (losses) arising during period	(11)	(530)	(19)	(341)
Less: reclassification adjustment for losses included in net income	0	0	(3)	0
Change in unrealized (losses) on investments	(11)	(530)	(16)	(341)
Income tax benefit	4	161	3	280
Unrealized (losses) on investments, net of tax	(7)	(369)	(13)	(61)
Changes in employee benefit related items:
Amortization of prior service cost	10	0	81	0
Recognized actuarial gain (loss)	391	238	(42)	475
Changes in employee benefit related items	401	238	39	475
Income tax expense	(4)	(3)	(75)	(65)
Employee benefit related items, net of tax	397	235	(36)	410
Other comprehensive (loss) income	(4,733)	5,922	53	(5,870)
Less: Comprehensive income (loss) in consolidated entities attributable to non-controlling interests	4,787	6,683	(910)	7,891
Comprehensive income attributable to AB Unitholders	$ 122,467	$ 155,008	$ 296,128	$ 284,752