Supplemental Guarantor / Non-Guarantor Financial Information Condensed Consolidating Statement of Comprehensive Income (Details) - USD ($) $ in Thousands		3 Months Ended				6 Months Ended
	Feb. 05, 2020	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues:
Revenues		$ 114,807		$ 130,751		$ 242,661	$ 265,248
Operating costs and expenses [Abstract]
Operations (exclusive of depreciation and amortization)		34,737		40,602		69,718	78,121
Depreciation and amortization		25,034		24,247		49,012	48,071
General and administrative		2,535		1,988		5,237	4,608
Total operating costs and expenses		62,306		66,837		123,967	130,800
Operating Income (Loss)		52,501		63,914		118,694	134,448
Equity in earnings of subsidiaries		0		0			0
Equity in earnings of equity method investments		2,156		1,783		3,870	3,883
Interest expense		(13,779)		(19,230)		(31,546)	(38,252)
Interest income		2,813		551		5,031	1,079
Gain (Loss) on Extinguishment of Debt	$ 25,900	0		0		(25,915)	0
Other Nonoperating Income (Expense)						974
Gain on Sales-type Leases		33,834		0		33,834	0
Gain on sale of assets and other		468		111		974	(199)
Nonoperating Income (Expense)		25,492		(16,785)		(13,752)	(33,489)
Income before income taxes		77,993		47,129		104,942	100,959
State income tax benefit (expense)		(39)		30		(76)	(6)
Net income		77,954	$ 26,912	47,159	$ 53,794	104,866	100,953
Allocation of net income attributable to noncontrolling interests		(1,484)		(1,469)		(3,535)	(4,081)
Net Income (Loss) Attributable to Parent		76,470		45,690		101,331	96,872
Other Comprehensive Income (Loss), Net of Tax						0
Net income attributable to the partners		76,470		45,690		101,331	96,872
Parent
Revenues:
Revenues		0		0		0	0
Operating costs and expenses [Abstract]
Operations (exclusive of depreciation and amortization)		0		0		0	0
Depreciation and amortization		0				0
General and administrative		780		745		1,879	1,821
Total operating costs and expenses		780		745		1,879	1,821
Operating Income (Loss)		(780)		(745)		(1,879)	(1,821)
Equity in earnings of subsidiaries		89,893		65,431			136,730
Equity in earnings of equity method investments		0		0		0	0
Interest expense		(12,740)		(18,996)		(29,470)	(38,037)
Interest income		26		0		26	0
Gain (Loss) on Extinguishment of Debt						(25,915)
Other Nonoperating Income (Expense)						141
Gain on Sales-type Leases		0				0
Gain on sale of assets and other		71		0			0
Nonoperating Income (Expense)		77,250		(46,435)		(103,210)	(98,693)
Income before income taxes		76,470		45,690		101,331	96,872
State income tax benefit (expense)		0		0		0	0
Net income		76,470		45,690		101,331	96,872
Allocation of net income attributable to noncontrolling interests		0		0		0	0
Other Comprehensive Income (Loss), Net of Tax						158,428
Net income attributable to the partners		76,470		45,690		101,331	96,872
Guarantor Restricted Subsidiaries
Revenues:
Revenues		105,304		119,921		219,214	239,379
Operating costs and expenses [Abstract]
Operations (exclusive of depreciation and amortization)		30,980		36,701		62,111	70,778
Depreciation and amortization		20,739		20,027		40,492	39,563
General and administrative		1,755		1,243		3,358	2,787
Total operating costs and expenses		53,474		57,971		105,961	113,128
Operating Income (Loss)		51,830		61,950		113,253	126,251
Equity in earnings of subsidiaries		1,510		2,063			7,559
Equity in earnings of equity method investments		1,449		1,783		3,537	3,883
Interest expense		(1,039)		(234)		(2,076)	(215)
Interest income		2,787		551		5,005	1,079
Gain (Loss) on Extinguishment of Debt						0
Other Nonoperating Income (Expense)						816
Gain on Sales-type Leases		33,834				33,834
Gain on sale of assets and other		396		69			(260)
Nonoperating Income (Expense)		38,937		4,232		46,921	12,046
Income before income taxes		90,767		66,182		160,174	138,297
State income tax benefit (expense)		(39)		30		(76)	(6)
Net income		90,728		66,212		160,098	138,291
Allocation of net income attributable to noncontrolling interests		(835)		(781)		(1,670)	(1,561)
Other Comprehensive Income (Loss), Net of Tax						5,805
Net income attributable to the partners		89,893		65,431		158,428	136,730
Non-Guarantor Non-Restricted Subsidiaries
Revenues:
Revenues		9,503		10,830		23,447	25,869
Operating costs and expenses [Abstract]
Operations (exclusive of depreciation and amortization)		3,757		3,901		7,607	7,343
Depreciation and amortization		4,295		4,220		8,520	8,508
General and administrative		0		0		0	0
Total operating costs and expenses		8,052		8,121		16,127	15,851
Operating Income (Loss)		1,451		2,709		7,320	10,018
Equity in earnings of subsidiaries		0		0			0
Equity in earnings of equity method investments		707		0		333	0
Interest expense		0		0		0	0
Interest income		0		0		0	0
Gain (Loss) on Extinguishment of Debt						0
Other Nonoperating Income (Expense)						17
Gain on Sales-type Leases		0				0
Gain on sale of assets and other		1		42			61
Nonoperating Income (Expense)		708		42		350	61
Income before income taxes		2,159		2,751		7,670	10,079
State income tax benefit (expense)		0		0		0	0
Net income		2,159		2,751		7,670	10,079
Allocation of net income attributable to noncontrolling interests		(649)		(688)		(1,865)	(2,520)
Other Comprehensive Income (Loss), Net of Tax						0
Net income attributable to the partners		1,510		2,063		5,805	7,559
Eliminations
Revenues:
Revenues		0		0		0	0
Operating costs and expenses [Abstract]
Operations (exclusive of depreciation and amortization)		0		0		0	0
Depreciation and amortization		0		0		0	0
General and administrative		0		0		0	0
Total operating costs and expenses		0		0		0	0
Operating Income (Loss)		0		0		0	0
Equity in earnings of subsidiaries		(91,403)		(67,494)			(144,289)
Equity in earnings of equity method investments		0		0		0	0
Interest expense		0		0		0	0
Interest income		0		0		0	0
Gain (Loss) on Extinguishment of Debt						0
Other Nonoperating Income (Expense)						0
Gain on Sales-type Leases		0				0
Gain on sale of assets and other		0		0			0
Nonoperating Income (Expense)		(91,403)		(67,494)		(164,233)	(144,289)
Income before income taxes		(91,403)		(67,494)		(164,233)	(144,289)
State income tax benefit (expense)		0		0		0	0
Net income		(91,403)		(67,494)		(164,233)	(144,289)
Allocation of net income attributable to noncontrolling interests		0		0		0	0
Other Comprehensive Income (Loss), Net of Tax						(164,233)
Net income attributable to the partners		(91,403)		(67,494)		(164,233)	(144,289)
Affiliates
Revenues:
Revenues		95,563		102,369		196,991	205,728
Affiliates | Parent
Revenues:
Revenues		0		0		0	0
Affiliates | Guarantor Restricted Subsidiaries
Revenues:
Revenues		89,417		96,221		184,172	193,614
Affiliates | Non-Guarantor Non-Restricted Subsidiaries
Revenues:
Revenues		6,146		6,148		12,819	12,114
Affiliates | Eliminations
Revenues:
Revenues		0		0		0	0
Third parties
Revenues:
Revenues		19,244		28,382		45,670	59,520
Third parties | Parent
Revenues:
Revenues		0		0		0	0
Third parties | Guarantor Restricted Subsidiaries
Revenues:
Revenues		15,887		23,700		35,042	45,765
Third parties | Non-Guarantor Non-Restricted Subsidiaries
Revenues:
Revenues		3,357		4,682		10,628	13,755
Third parties | Eliminations
Revenues:
Revenues		$ 0		$ 0		$ 0	$ 0