CONDENSED CONSOLIDATED STATEMENTS OF PARTNERS' CAPITAL - USD ($) $ in Thousands	Total	Accumulated Other Comprehensive (Loss) Income	Noncontrolling Interests	Limited Partners
Beginning balance at Dec. 31, 2017	$ 4,868,322	$ 28,631	$ 277,385	$ 4,562,306
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(534,927)		6,631	(541,558)
Acquisition of noncontrolling interest	(210,000)		(266,928)	56,928
Distributions paid to unitholders	(558,135)		2,020	(560,155)
Net proceeds from issuance of Units	262,002			262,002
Amortization of unit-based compensation awards	21,710			21,710
Payment of tax withholding on vesting of LTIP awards	(6,782)			(6,782)
Distributions paid to noncontrolling interests	(15,342)		(15,342)
Contributions from noncontrolling interests	7,400		7,400
Accrual for distribution equivalent rights	(1,194)			(1,194)
Other	(44)			(44)
Other comprehensive income	27,049	27,049
Ending balance at Sep. 30, 2018	3,860,059	55,680	11,166	3,793,213
Beginning balance at Jun. 30, 2018	4,779,589	48,580	11,249	4,719,760
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(745,336)		499	(745,835)
Acquisition of noncontrolling interest	0		78	(78)
Distributions paid to unitholders	(185,978)		648	(186,626)
Net proceeds from issuance of Units	(84)			(84)
Amortization of unit-based compensation awards	4,938			4,938
Payment of tax withholding on vesting of LTIP awards	(54)			(54)
Distributions paid to noncontrolling interests	(1,308)		(1,308)
Accrual for distribution equivalent rights	1,192			1,192
Other comprehensive income	7,100	7,100
Ending balance at Sep. 30, 2018	3,860,059	55,680	11,166	3,793,213
Beginning balance at Dec. 31, 2018	4,131,170	(40,061)	11,088	4,160,143
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	284,620		1,489	283,131
Distributions paid to unitholders	(347,706)		1,061	(348,767)
Amortization of unit-based compensation awards	21,630			21,630
Payment of tax withholding on vesting of LTIP awards	(2,343)			(2,343)
Distributions paid to noncontrolling interests	(2,809)		(2,809)
Accrual for distribution equivalent rights	(1,601)			(1,601)
Other	(3)		(138)	135
Other comprehensive income	7,378	7,378
Ending balance at Sep. 30, 2019	4,090,336	(32,683)	10,691	4,112,328
Beginning balance at Jun. 30, 2019	4,084,621	(37,012)	10,904	4,110,729
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	112,845		495	112,350
Distributions paid to unitholders	(115,928)		334	(116,262)
Amortization of unit-based compensation awards	5,949			5,949
Payment of tax withholding on vesting of LTIP awards	(33)			(33)
Distributions paid to noncontrolling interests	(904)		(904)
Accrual for distribution equivalent rights	(543)			(543)
Other	0		(138)	138
Other comprehensive income	4,329	4,329
Ending balance at Sep. 30, 2019	$ 4,090,336	$ (32,683)	$ 10,691	$ 4,112,328