Summary of Significant Accounting Policies - Summary of Balance Sheet Amounts Related to VIEs (Details) $ in Thousands	Dec. 31, 2016 USD ($) investment	Sep. 30, 2016 investment	Jan. 01, 2016 USD ($) investment	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Variable Interest Entity [Line Items]
Number of VIEs consolidated | investment		6
Cash and cash equivalents	$ 994,510			$ 541,483	$ 555,503	$ 509,891
Other assets	195,615			210,546
Total assets	8,740,448			7,433,721
Liabilities	4,279,300			3,403,297
Redeemable non-controlling interest	392,959			13,203
Partners’ capital attributable to AB Unitholders	4,032,017			3,992,748
Total liabilities and capital	8,740,448			$ 7,433,721
Net assets of non-consolidated VIEs	43,700,000
Maximum loss exposure	$ 13,000
Adjustments for New Accounting Principle, Early Adoption [Member]
Variable Interest Entity [Line Items]
Number of VIEs consolidated | investment	6		3
Accounting Standards Update 2015-02 [Member]
Variable Interest Entity [Line Items]
Cash and cash equivalents			$ 35,817
Investments			215,175
Other assets			13,871
Total assets			264,863
Liabilities			14,012
Redeemable non-controlling interest			250,851
Partners’ capital attributable to AB Unitholders			0
Total liabilities and capital			$ 264,863
VIEs Consolidated [Member] | Accounting Standards Update 2015-02 [Member]
Variable Interest Entity [Line Items]
Cash and cash equivalents	$ 371,457
Investments	85,381
Other assets	23,473
Total assets	480,311
Liabilities	41,245
Redeemable non-controlling interest	394,102
Partners’ capital attributable to AB Unitholders	44,964
Total liabilities and capital	480,311
VIEs Deconsolidated [Member] | Accounting Standards Update 2015-02 [Member]
Variable Interest Entity [Line Items]
Cash and cash equivalents	(12,923)
Investments	(125,636)
Other assets	(59,684)
Total assets	(198,243)
Liabilities	(60,332)
Redeemable non-controlling interest	(137,911)
Partners’ capital attributable to AB Unitholders	0
Total liabilities and capital	$ (198,243)