Changes in Capital (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Changes in capital [Roll Forward]
Partners' capital, beginning balance			$ 4,032,017
Partners' capital attributable to non-controlling interest, beginning balance			36,172
Partner's capital including portion attributable to non-controlling interest, beginning balance			4,068,189
Comprehensive income:
Net income	$ 152,272	$ 129,344	308,527	$ 289,880
Other comprehensive income, net of tax:
Foreign currency translation adjustments	7,489	(5,123)	16,356	102
Changes in employee benefit related items	267	397	456	(36)
Comprehensive income attributable to AB Unitholders	142,012	119,824	290,911	290,843
Distributions to General Partner and unitholders			(339,139)	(275,930)
Partners' capital, ending balance	3,886,114		3,886,114
Partners' capital attributable to non-controlling interest, ending balance	36,857		36,857
Partner's capital including portion attributable to non-controlling interest, ending balance	3,922,971		3,922,971
Partners’ Capital Attributable to AB Unitholders
Changes in capital [Roll Forward]
Partners' capital, beginning balance			4,032,017	3,992,748
Comprehensive income:
Net income			275,040	290,785
Other comprehensive income, net of tax:
Unrealized gains (losses) on investments			8	(13)
Foreign currency translation adjustments			15,407	107
Changes in employee benefit related items			456	(36)
Comprehensive income attributable to AB Unitholders			290,911	290,843
Distributions to General Partner and unitholders			(339,139)	(275,930)
Compensation-related transactions			(96,889)	(76,983)
Capital contributions to affiliates			(280)	(120)
Purchase of non-controlling interest			173
Distributions to non-controlling interests of our consolidated venture capital fund			0
Other			679	(337)
Partners' capital, ending balance	3,886,114	3,930,221	3,886,114	3,930,221
Non-Controlling Interests In Consolidated Entities
Changes in capital [Roll Forward]
Partners' capital attributable to non-controlling interest, beginning balance			36,172	24,473
Comprehensive income:
Net income attributable to noncontrolling interest			9,610	(6,953)
Other comprehensive income, net of tax:
Unrealized gains (losses) on investments			0	0
Foreign currency translation adjustments			949	(5)
Changes in employee benefit related items			0	0
Comprehensive income attributable to non-controlling interest			10,559	(6,958)
Distributions to General Partner and unitholders			0	0
Compensation-related transactions			0	0
Capital contributions to affiliates			0	0
Purchase of non-controlling interest			(2,006)
Distributions to non-controlling interests of our consolidated venture capital fund			(7,869)
Other			0	0
Partners' capital attributable to non-controlling interest, ending balance	36,857	17,515	36,857	17,515
Total Capital
Changes in capital [Roll Forward]
Partner's capital including portion attributable to non-controlling interest, beginning balance			4,068,189	4,017,221
Comprehensive income:
Net income			284,650	283,832
Other comprehensive income, net of tax:
Unrealized gains (losses) on investments			8	(13)
Foreign currency translation adjustments			16,356	102
Changes in employee benefit related items			456	(36)
Comprehensive income			301,470	283,885
Distributions to General Partner and unitholders			(339,139)	(275,930)
Compensation-related transactions			(96,889)	(76,983)
Capital contributions to affiliates			(280)	(120)
Purchase of non-controlling interest			(1,833)
Distributions to non-controlling interests of our consolidated venture capital fund			(7,868)
Other			679	(337)
Partner's capital including portion attributable to non-controlling interest, ending balance	$ 3,922,971	3,947,736	$ 3,922,971	3,947,736
Adjustment
Other comprehensive income, net of tax:
Partners' capital, ending balance		$ (43,000)		$ (43,000)