Summary of Significant Accounting Policies - Revision (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015		Sep. 30, 2015	[1]	Jun. 30, 2015	[1]	Mar. 31, 2015	[1]	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jan. 01, 2012
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Partners’ capital attributable to AB Unitholders	$ 4,032,017				$ 3,992,748								$ 4,032,017	$ 3,992,748
Income taxes													28,319	44,797	$ 44,304
Net income attributable to AB Unitholders	$ 224,538	$ 158,035	$ 124,501	$ 166,284	$ 159,394	[1]	$ 133,308		$ 147,425		$ 139,800		$ 673,358	$ 579,927	$ 563,861
Basic net income per AB Unit (in dollars per unit)	$ 0.83	$ 0.58	$ 0.46	$ 0.61	$ 0.59	[1],[2]	$ 0.49	[2]	$ 0.53	[2]	$ 0.51	[2]	$ 2.48	$ 2.11	$ 2.07
Diluted net income per AB Unit (in dollars per unit)	$ 0.83	$ 0.58	$ 0.46	$ 0.60	$ 0.58	[1],[2]	$ 0.48	[2]	$ 0.53	[2]	$ 0.51	[2]	$ 2.47	$ 2.10	$ 2.07
As Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Income taxes														$ 38,122	$ 37,782
Net income attributable to AB Unitholders														$ 586,602	$ 570,383
Basic net income per AB Unit (in dollars per unit)														$ 2.14	$ 2.10
Diluted net income per AB Unit (in dollars per unit)														$ 2.13	$ 2.09
Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Partners’ capital attributable to AB Unitholders					$ (37,700)									$ (37,700)	$ (31,000)	$ (24,500)	$ (12,600)
Income tax liability arising from prior period restatement	$ 34,200												$ 34,200
Income taxes														6,675	6,522
Net income attributable to AB Unitholders														$ (6,675)	$ (6,522)
Basic net income per AB Unit (in dollars per unit)														$ (0.03)	$ (0.03)
Diluted net income per AB Unit (in dollars per unit)														$ (0.03)	$ (0.02)

[1] Certain prior-period amounts have been revised, see Note 2 for a discussion of the revision.

[2] Basic and diluted net income per unit are computed independently for each of the periods presented. Accordingly, the sum of the quarterly net income per unit amounts may not agree to the total for the year.