Condensed Statement of Changes in Partners' Capital - USD ($) $ in Thousands	Total	AB Holding Units held by AB to fund long-term incentive compensation plans	Accumulated Other Comprehensive Income (Loss)	General Partner	Limited Partner
Balance, beginning of period at Dec. 31, 2017		$ (15,174)	$ (33,463)	$ 1,411	$ 1,590,776
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 116,617			119	116,498
Cash distributions to Unitholders				(157)	(153,907)
Retirement of AB Holding Units					(39,704)
Issuance of AB Holding Units to fund long-term incentive compensation plan awards					67,579
Exercise of compensatory options to buy AB Holding Units					8,314
Other			133		(133)
AB Holding Units held by AB to fund long-term incentive compensation plans		(16,544)
Foreign currency translation adjustment, net of tax			(3,970)
Changes in employee benefit related items, net of tax			(20)
Balance, end of period at Jun. 30, 2018	1,534,306	(31,718)	(37,320)	1,386	1,601,958
Balance, beginning of period at Mar. 31, 2018		(20,551)	(30,115)	1,400	1,609,974
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	58,457			59	58,398
Cash distributions to Unitholders				(73)	(72,190)
Retirement of AB Holding Units					(39,637)
Issuance of AB Holding Units to fund long-term incentive compensation plan awards					41,241
Exercise of compensatory options to buy AB Holding Units					4,306
Other			134		(134)
AB Holding Units held by AB to fund long-term incentive compensation plans		(11,167)
Foreign currency translation adjustment, net of tax			(7,398)
Changes in employee benefit related items, net of tax			59
Balance, end of period at Jun. 30, 2018	1,534,306	(31,718)	(37,320)	1,386	1,601,958
Balance, beginning of period at Dec. 31, 2018	1,490,057	(27,759)	(39,461)	1,385	1,555,892
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	98,713			103	98,610
Cash distributions to Unitholders				(113)	(108,055)
Retirement of AB Holding Units					(73,383)
Issuance of AB Holding Units to fund long-term incentive compensation plan awards	60,903				60,903
Exercise of compensatory options to buy AB Holding Units					8,951
Other			0		0
AB Holding Units held by AB to fund long-term incentive compensation plans		(7,987)
Foreign currency translation adjustment, net of tax			114
Changes in employee benefit related items, net of tax			217
Balance, end of period at Jun. 30, 2019	1,469,417	(35,746)	(39,130)	1,375	1,542,918
Balance, beginning of period at Mar. 31, 2019		(24,464)	(38,018)	1,370	1,490,581
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	52,274			55	52,219
Cash distributions to Unitholders				(50)	(47,311)
Retirement of AB Holding Units					(3,730)
Issuance of AB Holding Units to fund long-term incentive compensation plan awards					49,590
Exercise of compensatory options to buy AB Holding Units					1,569
Other			0		0
AB Holding Units held by AB to fund long-term incentive compensation plans		(11,282)
Foreign currency translation adjustment, net of tax			(1,036)
Changes in employee benefit related items, net of tax			(76)
Balance, end of period at Jun. 30, 2019	$ 1,469,417	$ (35,746)	$ (39,130)	$ 1,375	$ 1,542,918