Changes in Capital (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 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	$ 157,480	$ 173,731	466,007	$ 463,611
Other comprehensive income, net of tax:
Foreign currency translation adjustments	7,735	443	24,091	545
Changes in employee benefit related items	299	274	755	238
Comprehensive income attributable to AB Unitholders	148,961	158,734	439,872	449,577
Distributions to General Partner and unitholders			(489,049)	(400,441)
Proceeds from Contributions from Affiliates			79	439
Partners' capital, ending balance	3,894,781		3,894,781
Partners' capital attributable to non-controlling interest, ending balance	1,607		1,607
Partner's capital including portion attributable to non-controlling interest, ending balance	3,896,388		3,896,388
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			415,994	448,820
Other comprehensive income, net of tax:
Unrealized gains (losses) on investments			9	(2)
Foreign currency translation adjustments			23,114	521
Changes in employee benefit related items			755	238
Comprehensive income attributable to AB Unitholders			439,872	449,577
Distributions to General Partner and unitholders			(489,049)	(400,441)
Compensation-related transactions			(89,567)	(119,877)
Proceeds from Contributions from Affiliates			79	439
Purchase of non-controlling interest			172
Distributions to non-controlling interests of our consolidated venture capital fund			0
Other			1,257	1,742
Partners' capital, ending balance	3,894,781	3,924,188	3,894,781	3,924,188
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			9,680	5,689
Other comprehensive income, net of tax:
Unrealized gains (losses) on investments			0	0
Foreign currency translation adjustments			977	24
Changes in employee benefit related items			0	0
Comprehensive income attributable to non-controlling interest			10,657	5,713
Distributions to General Partner and unitholders			0	0
Compensation-related transactions			0	0
Capital contributions from affiliates			0	0
Purchase of non-controlling interest			(2,005)
Distributions to non-controlling interests of our consolidated venture capital fund			(43,217)
Other			0	363
Partners' capital attributable to non-controlling interest, ending balance	1,607	30,549	1,607	30,549
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			425,674	454,509
Other comprehensive income, net of tax:
Unrealized gains (losses) on investments			9	(2)
Foreign currency translation adjustments			24,091	545
Changes in employee benefit related items			755	238
Comprehensive income			450,529	455,290
Distributions to General Partner and unitholders			(489,049)	(400,441)
Compensation-related transactions			(89,567)	(119,877)
Proceeds from Contributions from Affiliates			79	439
Purchase of non-controlling interest			(1,833)
Distributions to non-controlling interests of our consolidated venture capital fund			(43,217)
Other			1,257	2,105
Partner's capital including portion attributable to non-controlling interest, ending balance	$ 3,896,388	$ 3,954,737	$ 3,896,388	$ 3,954,737