Consolidated Statements of Changes in Partners' Capital - USD ($) $ in Thousands	Total	Receivables from Affiliates	AB Holding Units held for Long-term Incentive Compensation Plans	Accumulated Other Comprehensive Income (Loss)	Total Partners' Capital attributable to AB Unitholders	Non-redeemable Non-controlling Interests in Consolidated Entities	General Partner’s Capital	General Partner’s Capital Cumulative Effect, Period of Adoption, Adjustment	Limited Partners' Capital	Limited Partners' Capital Cumulative Effect, Period of Adoption, Adjustment
Balance, beginning of year at Dec. 31, 2017		$ (11,494)	$ (42,688)	$ (94,140)		$ 1,564	$ 41,221	$ 349	$ 4,168,841	$ 34,601
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 779,498						7,576		750,012
Cash distributions							(8,608)		(849,585)
Long-term incentive compensation plans activity		0					(39)		(3,880)
Retirement of AB Units, net			25,589				(256)		(25,486)
Other			0	374			(3)		803
Capital contributions from General Partner		19
Compensation plan accrual		352
Capital contributions from AB Holding		(307)
Purchases of AB Holding Units to fund long-term compensation plans, net			(267,427)
Long-term incentive compensation awards expense			187,514
Re-valuation of AB Holding Units held in rabbi trust			19,022
Changes in employee benefit related items, net of tax	1,471			1,471
Unrealized gain on investments, net of tax				0
Net income	21,910					69
Foreign currency translation adjustment	(18,617)			(18,571)		(46)
Purchase of non-controlling interest						0
Distributions (to) non-controlling interests of our consolidated venture capital fund activities						(638)
Balance, end of year at Dec. 31, 2018	3,916,209	(11,430)	(77,990)	(110,866)	$ 3,915,260	949	40,240	0	4,075,306	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	781,683						7,521		744,521
Cash distributions							(7,042)		(696,470)
Long-term incentive compensation plans activity		1,125					149		14,741
Issuance of AB Units, net			(35,736)				357		35,259
Other			6,692	0			0		844
Capital contributions from General Partner		0
Compensation plan accrual		0
Capital contributions from AB Holding		1,294
Purchases of AB Holding Units to fund long-term compensation plans, net			(171,930)
Long-term incentive compensation awards expense			207,057
Re-valuation of AB Holding Units held in rabbi trust			(4,403)
Changes in employee benefit related items, net of tax	(7,593)			(7,593)
Unrealized gain on investments, net of tax				0
Net income	29,641					91
Foreign currency translation adjustment	5,603			5,455		147
Purchase of non-controlling interest						(1,187)
Distributions (to) non-controlling interests of our consolidated venture capital fund activities						0
Balance, end of year at Dec. 31, 2019	4,017,101	(9,011)	(76,310)	(113,004)	4,017,101	0	41,225	$ 0	4,174,201	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	861,783						8,660		857,292
Cash distributions							(8,376)		(828,503)
Long-term incentive compensation plans activity		802					(23)		(2,147)
Issuance of AB Units, net			(28,696)
Retirement of AB Units, net							290		28,642
Other			15	0			0		0
Capital contributions from General Partner		0
Compensation plan accrual		0
Capital contributions from AB Holding		(107)
Purchases of AB Holding Units to fund long-term compensation plans, net			(148,624)
Long-term incentive compensation awards expense			194,840
Re-valuation of AB Holding Units held in rabbi trust			1,556
Changes in employee benefit related items, net of tax	(4,443)			(4,443)
Unrealized gain on investments, net of tax				0
Net income	(4,169)					0
Foreign currency translation adjustment	23,244			23,244		0
Purchase of non-controlling interest						0
Distributions (to) non-controlling interests of our consolidated venture capital fund activities						0
Balance, end of year at Dec. 31, 2020	$ 4,111,523	$ (8,316)	$ (57,219)	$ (94,203)	$ 4,111,523	$ 0	$ 41,776		$ 4,229,485