Changes in Capital (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Changes in capital [Roll Forward]
Partners' capital, beginning balance	$ 3,915,260
Partners' capital attributable to non-controlling interest, beginning balance	949
Partner's capital including portion attributable to non-controlling interest, beginning balance	3,916,209
Comprehensive income:
Net income	159,230	$ 206,846
Other comprehensive income, net of tax:
Foreign currency translation adjustments	2,553	9,921
Changes in employee benefit related items	283	170
Comprehensive income attributable to AB Unitholders	151,970	194,270
Distributions to General Partner and unitholders	(191,485)	(247,773)
Partners' capital, ending balance	3,842,812
Partners' capital attributable to non-controlling interest, ending balance	945
Partner's capital including portion attributable to non-controlling interest, ending balance	3,843,757
Partners’ Capital Attributable to AB Unitholders
Changes in capital [Roll Forward]
Partners' capital, beginning balance	3,915,260	4,061,740
Comprehensive income:
Net income	149,114	184,196
Other comprehensive income, net of tax:
Foreign currency translation adjustments	2,573	9,904
Changes in employee benefit related items	283	170
Comprehensive income attributable to AB Unitholders	151,970	194,270
Distributions to General Partner and unitholders	(191,485)	(247,773)
Compensation-related transactions	(32,001)	14,334
Capital contributions to affiliates	(932)
Capital contributions from affiliates		(1,677)
Distributions to non-controlling interests of our consolidated venture capital fund		0
Partners' capital, ending balance	3,842,812	4,055,845
Non-Redeemable Non-Controlling Interests In Consolidated Entities
Changes in capital [Roll Forward]
Partners' capital attributable to non-controlling interest, beginning balance	949	1,564
Comprehensive income:
Net income attributable to noncontrolling interest	16	54
Other comprehensive income, net of tax:
Foreign currency translation adjustments	(20)	17
Changes in employee benefit related items	0	0
Comprehensive income attributable to non-controlling interest	(4)	71
Distributions to General Partner and unitholders	0	0
Compensation-related transactions	0	0
Capital contributions to affiliates	0
Capital contributions from affiliates		0
Distributions to non-controlling interests of our consolidated venture capital fund		(5)
Partners' capital attributable to non-controlling interest, ending balance	945	1,630
Total Capital
Changes in capital [Roll Forward]
Partner's capital including portion attributable to non-controlling interest, beginning balance	3,916,209	4,063,304
Comprehensive income:
Net income	149,130	184,250
Other comprehensive income, net of tax:
Foreign currency translation adjustments	2,553	9,921
Changes in employee benefit related items	283	170
Comprehensive income	151,966	194,341
Distributions to General Partner and unitholders	(191,485)	(247,773)
Compensation-related transactions	(32,001)	14,334
Capital contributions to affiliates	(932)
Capital contributions from affiliates		(1,677)
Distributions to non-controlling interests of our consolidated venture capital fund		(5)
Partner's capital including portion attributable to non-controlling interest, ending balance	$ 3,843,757	4,057,475
Difference between Revenue Guidance in Effect before and after Topic 606 | ASC 606 | Partners’ Capital Attributable to AB Unitholders
Other comprehensive income, net of tax:
Impact of adoption of revenue recognition standard ASC 606		34,951
Difference between Revenue Guidance in Effect before and after Topic 606 | ASC 606 | Non-Redeemable Non-Controlling Interests In Consolidated Entities
Other comprehensive income, net of tax:
Impact of adoption of revenue recognition standard ASC 606		0
Difference between Revenue Guidance in Effect before and after Topic 606 | ASC 606 | Total Capital
Other comprehensive income, net of tax:
Impact of adoption of revenue recognition standard ASC 606		$ 34,951