CONSOLIDATED STATEMENTS OF PARTNERS' CAPITAL - USD ($) $ in Thousands	Total	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest	Limited Partners
Beginning balance at Dec. 31, 2015	$ 4,016,741	$ (97,841)	$ 281,352	$ 3,833,230
Increase (Decrease) in Partners' Capital [Roll Forward]
Net (loss) income	548,675		13,067	535,608
Distributions paid to unitholders	(641,686)		3,043	(644,729)
Net proceeds from issuance of LP Units	689,128			689,128
Amortization of unit-based compensation awards	33,482			33,482
Net proceeds from exercise of Unit options	300			300
Payment of tax withholding on issuance of LTIP awards	(6,711)			(6,711)
Distributions paid to noncontrolling interests	(15,750)		(15,750)
Contributions from noncontrolling interests	5,000		5,000
Other comprehensive income (loss)	72,248	72,248
Accrual of distribution equivalent rights	(3,004)			(3,004)
Other			(12)	12
Ending balance at Dec. 31, 2016	4,698,423	(25,593)	286,700	4,437,316
Increase (Decrease) in Partners' Capital [Roll Forward]
Net (loss) income	493,665		14,863	478,802
Distributions paid to unitholders	(714,495)		2,898	(717,393)
Net proceeds from issuance of LP Units	345,795			345,795
Amortization of unit-based compensation awards	30,568			30,568
Net proceeds from exercise of Unit options	481			481
Payment of tax withholding on issuance of LTIP awards	(9,447)			(9,447)
Distributions paid to noncontrolling interests	(39,230)		(39,230)
Contributions from noncontrolling interests	12,000		12,000
Other comprehensive income (loss)	54,224	54,224
Accrual of distribution equivalent rights	(3,662)			(3,662)
Other			154	(154)
Ending balance at Dec. 31, 2017	4,868,322	28,631	277,385	4,562,306
Increase (Decrease) in Partners' Capital [Roll Forward]
Net (loss) income	(51,915)		7,123	(59,038)
Acquisition of noncontrolling interest	(210,000)		(266,928)	56,928
Distributions paid to unitholders	(673,723)		2,400	(676,123)
Net proceeds from issuance of LP Units	261,962			261,962
Amortization of unit-based compensation awards	22,081			22,081
Payment of tax withholding on issuance of LTIP awards	(8,306)			(8,306)
Distributions paid to noncontrolling interests	(16,292)		(16,292)
Contributions from noncontrolling interests	7,400		7,400
Other comprehensive income (loss)	(68,692)	(68,692)
Accrual of distribution equivalent rights	333			333
Ending balance at Dec. 31, 2018	$ 4,131,170	$ (40,061)	$ 11,088	$ 4,160,143