Condensed 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)	Partners' Capital	Non-redeemable Non-controlling Interests in Consolidated Entities	General Partner’s Capital	Limited Partners' Capital
Balance, beginning of period at Dec. 31, 2017		$ (11,494)	$ (42,688)	$ (94,140)		$ 1,564	$ 41,221	$ 4,168,841
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 388,772					118	3,658	362,203
Cash distributions							(4,670)	(461,852)
Long-term incentive compensation plans activity		0	14,825				52	5,036
Issuance (retirement) of AB Units, net			(27,875)				279	27,491
Other			0	374			(3)	(370)
Capital contributions from General Partner		19
Purchases of AB Holding Units to fund long-term compensation plans, net			(34,864)
Compensation plan accrual		352
Capital contributions from AB Holding		(582)
Re-valuation of AB Holding Units held in rabbi trust			2,285
Foreign currency translation adjustment, net of tax	(10,635)			(10,612)		(23)
Changes in employee benefit related items, net of tax	463			463
Distributions from non-controlling interests of our consolidated venture capital fund activities						0
Balance, end of period at Jun. 30, 2018	3,974,558	(11,705)	(88,317)	(103,915)	$ 3,972,899	1,659	40,886	4,135,950
Balance, beginning of period at Mar. 31, 2018		(12,489)	(57,366)	(84,066)		1,630	41,218	4,168,548
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	181,926					63	1,816	179,849
Cash distributions							(2,191)	(216,558)
Long-term incentive compensation plans activity		0	2,341				30	2,968
Issuance (retirement) of AB Units, net			(1,604)				16	1,513
Other			0	374			(3)	(370)
Capital contributions from General Partner		0
Purchases of AB Holding Units to fund long-term compensation plans, net			(32,737)
Compensation plan accrual		0
Capital contributions from AB Holding		784
Re-valuation of AB Holding Units held in rabbi trust			1,049
Foreign currency translation adjustment, net of tax	(20,556)			(20,516)		(39)
Changes in employee benefit related items, net of tax	293			293
Distributions from non-controlling interests of our consolidated venture capital fund activities						5
Balance, end of period at Jun. 30, 2018	3,974,558	(11,705)	(88,317)	(103,915)	3,972,899	1,659	40,886	4,135,950
Balance, beginning of period at Dec. 31, 2018		(11,430)	(77,990)	(110,866)		949	40,240	4,075,306
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	333,239					74	3,154	312,212
Cash distributions							(3,438)	(340,033)
Long-term incentive compensation plans activity		692	26,615				185	18,255
Issuance (retirement) of AB Units, net			12,480				(125)	(12,380)
Other			6,692	0			0	0
Capital contributions from General Partner		0
Purchases of AB Holding Units to fund long-term compensation plans, net			(58,358)
Compensation plan accrual		0
Capital contributions from AB Holding		899
Re-valuation of AB Holding Units held in rabbi trust			(9,892)
Foreign currency translation adjustment, net of tax	302			304		(3)
Changes in employee benefit related items, net of tax	599			599
Distributions from non-controlling interests of our consolidated venture capital fund activities						0
Balance, end of period at Jun. 30, 2019	3,874,141	(9,839)	(100,453)	(109,963)	3,873,121	1,020	40,016	4,053,360
Balance, beginning of period at Mar. 31, 2019		(11,666)	(69,503)	(108,012)		945	39,403	3,992,590
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	174,009					58	1,663	164,589
Cash distributions							(1,521)	(150,465)
Long-term incentive compensation plans activity		227	8,011				12	1,270
Issuance (retirement) of AB Units, net			(45,860)				459	45,376
Other			6,692	0			0	0
Capital contributions from General Partner		0
Purchases of AB Holding Units to fund long-term compensation plans, net			94
Compensation plan accrual		0
Capital contributions from AB Holding		1,600
Re-valuation of AB Holding Units held in rabbi trust			113
Foreign currency translation adjustment, net of tax	(2,251)			(2,267)		17
Changes in employee benefit related items, net of tax	316			316
Distributions from non-controlling interests of our consolidated venture capital fund activities						0
Balance, end of period at Jun. 30, 2019	$ 3,874,141	$ (9,839)	$ (100,453)	$ (109,963)	$ 3,873,121	$ 1,020	$ 40,016	$ 4,053,360