Changes in Capital (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Changes in capital [Roll Forward]
Partners' capital, beginning balance			$ 4,085,465
Partners' capital attributable to non-controlling interest, beginning balance			30,396
Partner's capital including portion attributable to non-controlling interest, beginning balance			4,115,861
Comprehensive income:
Net income	$ 131,905	$ 135,298	430,418	$ 390,268
Other comprehensive income, net of tax:
Foreign currency translation adjustments	(7,161)	(15,081)	(13,380)	(8,982)
Changes in employee benefit related items	229	(794)	639	(2,429)
Comprehensive income attributable to AB Unitholders	127,221	124,091	411,973	382,241
Distributions to General Partner and unitholders			(461,956)	(433,917)
Purchases of AB Units			(802)	(1,375)
Partners' capital, ending balance	3,958,505		3,958,505
Partners' capital attributable to non-controlling interest, ending balance	25,019		25,019
Partner's capital including portion attributable to non-controlling interest, ending balance	3,983,524		3,983,524
Partners’ Capital Attributable to AB Unitholders
Changes in capital [Roll Forward]
Partners' capital, beginning balance			4,085,465	4,027,486
Comprehensive income:
Net income			425,539	392,958
Other comprehensive income, net of tax:
Unrealized gains (losses) on investments			(922)	644
Foreign currency translation adjustments			(13,283)	(8,932)
Changes in employee benefit related items			639	(2,429)
Comprehensive income attributable to AB Unitholders			411,973	382,241
Distributions to General Partner and unitholders			(461,956)	(433,917)
Distributions from non-controlling interests			0
Distributions to non-controlling interests				0
Purchases of AB Units			(802)	(1,375)
Compensation-related transactions			(78,489)	23,269
Other			2,314	(129)
Partners' capital, ending balance	3,958,505	3,997,575	3,958,505	3,997,575
Non-Controlling Interests In Consolidated Entities
Changes in capital [Roll Forward]
Partners' capital attributable to non-controlling interest, beginning balance			30,396	42,240
Comprehensive income:
Net income			4,879	(2,690)
Other comprehensive income, net of tax:
Unrealized gains (losses) on investments			0	0
Foreign currency translation adjustments			(97)	(50)
Changes in employee benefit related items			0	0
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest			4,782	(2,740)
Distributions to General Partner and unitholders			0	0
Distributions from non-controlling interests			(10,159)
Distributions to non-controlling interests				(11,375)
Purchases of AB Units			0	0
Compensation-related transactions			0	0
Other			0	0
Partners' capital attributable to non-controlling interest, ending balance	25,019	28,125	25,019	28,125
Total Capital
Changes in capital [Roll Forward]
Partner's capital including portion attributable to non-controlling interest, beginning balance			4,115,861	4,069,726
Comprehensive income:
Net income			430,418	390,268
Other comprehensive income, net of tax:
Unrealized gains (losses) on investments			(922)	644
Foreign currency translation adjustments			(13,380)	(8,982)
Changes in employee benefit related items			639	(2,429)
Comprehensive income			416,755	379,501
Distributions to General Partner and unitholders			(461,956)	(433,917)
Distributions from non-controlling interests			(10,159)
Distributions to non-controlling interests				(11,375)
Purchases of AB Units			(802)	(1,375)
Compensation-related transactions			(78,489)	23,269
Other			2,314	(129)
Partner's capital including portion attributable to non-controlling interest, ending balance	$ 3,983,524	$ 4,025,700	$ 3,983,524	$ 4,025,700