Changes in Capital (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018
Changes in capital [Roll Forward]
Partners' capital, beginning balance	$ 4,061,740
Partners' capital attributable to non-controlling interest, beginning balance	1,564
Partner's capital including portion attributable to non-controlling interest, beginning balance	4,063,304
Comprehensive income:
Net income	206,846	$ 156,255
Other comprehensive income, net of tax:
Foreign currency translation adjustments	9,921	8,867
Changes in employee benefit related items	170	189
Comprehensive income attributable to AB Unitholders	194,270	148,899
Distributions to General Partner and unitholders	(247,773)	(198,040)
Partners' capital, ending balance	4,055,845
Partners' capital attributable to non-controlling interest, ending balance	1,630
Partner's capital including portion attributable to non-controlling interest, ending balance	4,057,475
Partners’ Capital Attributable to AB Unitholders
Changes in capital [Roll Forward]
Partners' capital, beginning balance	4,061,740	4,032,017
Comprehensive income:
Net income	184,196	139,937
Other comprehensive income, net of tax:
Unrealized gains (losses) on investments	0	(18)
Foreign currency translation adjustments	9,904	8,791
Changes in employee benefit related items	170	189
Comprehensive income attributable to AB Unitholders	194,270	148,899
Distributions to General Partner and unitholders	(247,773)	(198,040)
Compensation-related transactions	14,334	(18,673)
Capital contributions to affiliates	(1,677)	(81)
Distributions to non-controlling interests of our consolidated venture capital fund	0	0
Partners' capital, ending balance	4,055,845	3,964,122
Non-Controlling Interests In Consolidated Entities
Changes in capital [Roll Forward]
Partners' capital attributable to non-controlling interest, beginning balance	1,564	36,172
Comprehensive income:
Net income attributable to noncontrolling interest	54	1,632
Other comprehensive income, net of tax:
Unrealized gains (losses) on investments	0	0
Foreign currency translation adjustments	17	76
Changes in employee benefit related items	0	0
Comprehensive income attributable to non-controlling interest	71	1,708
Distributions to General Partner and unitholders	0	0
Compensation-related transactions	0	0
Capital contributions to affiliates	0	0
Distributions to non-controlling interests of our consolidated venture capital fund	(5)	(3,137)
Partners' capital attributable to non-controlling interest, ending balance	1,630	34,743
Total Capital
Changes in capital [Roll Forward]
Partner's capital including portion attributable to non-controlling interest, beginning balance	4,063,304	4,068,189
Comprehensive income:
Net income	184,250	141,569
Other comprehensive income, net of tax:
Unrealized gains (losses) on investments	0	(18)
Foreign currency translation adjustments	9,921	8,867
Changes in employee benefit related items	170	189
Comprehensive income	194,341	150,607
Distributions to General Partner and unitholders	(247,773)	(198,040)
Compensation-related transactions	14,334	(18,673)
Capital contributions to affiliates	(1,677)	(81)
Distributions to non-controlling interests of our consolidated venture capital fund	(5)	(3,137)
Partner's capital including portion attributable to non-controlling interest, ending balance	4,057,475	$ 3,998,865
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Other comprehensive income, net of tax:
Impact of adoption of revenue recognition standard ASC 606	35,000		$ 35,000
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09 | 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 | Accounting Standards Update 2014-09 | 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 | Accounting Standards Update 2014-09 | Total Capital
Other comprehensive income, net of tax:
Impact of adoption of revenue recognition standard ASC 606	$ 34,951