Supplemental Guarantor Financial Information - I/S (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Condensed Consolidated Statements of Comprehensive (Loss) Income
Revenues	$ 233,192	$ 340,821	$ 539,794	$ 659,091	$ 1,349,405
Operating costs and expenses	235,826		525,759
Loss on disposal and impairment of assets	112	1,496	1,033	2,464
(Loss) income from operations	(2,746)	25,689	13,002	35,863	86,434
Interest expense (income), net, including amortization of deferred financing costs and note discount	13,208		23,115
Loss on extinguishment of convertible notes	3,018	0	3,018	0
Equity in earnings of subsidiaries	0		0
Other (income) expenses	(6,364)	1,456	(2,535)	(5,751)
(Loss) income before income taxes	(12,608)	14,032	(10,596)	21,478
Income tax (benefit) expense	(10,687)	3,565	(14,424)	6,694
Net income (loss)	(1,921)	10,467	3,828	14,784	48,265
Net loss attributable to noncontrolling interests	1	(4)	(5)	(6)
Net income (loss) attributable to controlling interests and available to common shareholders	(1,922)	10,471	3,833	14,790	48,274
Other comprehensive (loss) income attributable to controlling interest	(1,478)		(60,981)
Comprehensive (loss) income attributable to controlling interests	(3,400)	$ 1,140	(57,148)	$ (2,144)
Eliminations
Condensed Consolidated Statements of Comprehensive (Loss) Income
Revenues	(16,533)		(34,002)		(72,531)
Operating costs and expenses	(16,829)		(34,738)
(Loss) income from operations	296		736		300
Interest expense (income), net, including amortization of deferred financing costs and note discount	53		115
Loss on extinguishment of convertible notes	0		0
Equity in earnings of subsidiaries	(4,418)		22,795
Other (income) expenses	(5,798)		(13,397)
(Loss) income before income taxes	10,459		(8,777)
Income tax (benefit) expense	0		0
Net income (loss)	10,459		(8,777)		(111,534)
Net loss attributable to noncontrolling interests	1		(5)
Net income (loss) attributable to controlling interests and available to common shareholders	10,458		(8,772)		(111,525)
Other comprehensive (loss) income attributable to controlling interest	(54,595)		10,361
Comprehensive (loss) income attributable to controlling interests	(44,137)		1,589
Parent | Reportable Legal Entities
Condensed Consolidated Statements of Comprehensive (Loss) Income
Revenues	0		0		0
Operating costs and expenses	5,540		11,336
(Loss) income from operations	(5,540)		(11,336)		(35,637)
Interest expense (income), net, including amortization of deferred financing costs and note discount	0		0
Loss on extinguishment of convertible notes	0		0
Equity in earnings of subsidiaries	(788)		(13,441)
Other (income) expenses	(2,196)		532
(Loss) income before income taxes	(2,556)		1,573
Income tax (benefit) expense	(635)		(2,255)
Net income (loss)	(1,921)		3,828		48,265
Net loss attributable to noncontrolling interests	0		0
Net income (loss) attributable to controlling interests and available to common shareholders	(1,921)		3,828		48,265
Other comprehensive (loss) income attributable to controlling interest	(1,478)		(60,981)
Comprehensive (loss) income attributable to controlling interests	(3,399)		(57,153)
Issuer | Reportable Legal Entities
Condensed Consolidated Statements of Comprehensive (Loss) Income
Revenues	143,778		305,168		668,527
Operating costs and expenses	143,939		298,857
Loss on disposal and impairment of assets	122		539
(Loss) income from operations	(283)		5,772		40,733
Interest expense (income), net, including amortization of deferred financing costs and note discount	11,500		20,102
Loss on extinguishment of convertible notes	3,018		3,018
Equity in earnings of subsidiaries	(8,096)		(25,684)
Other (income) expenses	3,604		11,300
(Loss) income before income taxes	(10,309)		(2,964)
Income tax (benefit) expense	(10,311)		(12,600)
Net income (loss)	2		9,636		20,546
Net loss attributable to noncontrolling interests	0		0
Net income (loss) attributable to controlling interests and available to common shareholders	2		9,636		20,546
Other comprehensive (loss) income attributable to controlling interest	(1,915)		(34,422)
Comprehensive (loss) income attributable to controlling interests	(1,913)		(24,786)
Guarantors | Reportable Legal Entities
Condensed Consolidated Statements of Comprehensive (Loss) Income
Revenues	56,717		134,853		351,330
Operating costs and expenses	43,516		104,643
Loss on disposal and impairment of assets	22		126
(Loss) income from operations	13,179		30,084		70,835
Interest expense (income), net, including amortization of deferred financing costs and note discount	3,311		4,512
Loss on extinguishment of convertible notes	0		0
Equity in earnings of subsidiaries	13,292		16,079
Other (income) expenses	332		6,874
(Loss) income before income taxes	(3,756)		2,619
Income tax (benefit) expense	1,602		1,188
Net income (loss)	(5,358)		1,431		63,952
Net loss attributable to noncontrolling interests	0		0
Net income (loss) attributable to controlling interests and available to common shareholders	(5,358)		1,431		63,952
Other comprehensive (loss) income attributable to controlling interest	7,905		12,193
Comprehensive (loss) income attributable to controlling interests	2,547		13,624
Non-Guarantors | Reportable Legal Entities
Condensed Consolidated Statements of Comprehensive (Loss) Income
Revenues	49,230		133,775		402,079
Operating costs and expenses	59,660		145,661
Loss on disposal and impairment of assets	(32)		368
(Loss) income from operations	(10,398)		(12,254)		10,203
Interest expense (income), net, including amortization of deferred financing costs and note discount	(1,656)		(1,614)
Loss on extinguishment of convertible notes	0		0
Equity in earnings of subsidiaries	10		251
Other (income) expenses	(2,306)		(7,844)
(Loss) income before income taxes	(6,446)		(3,047)
Income tax (benefit) expense	(1,343)		(757)
Net income (loss)	(5,103)		(2,290)		27,036
Net loss attributable to noncontrolling interests	0		0
Net income (loss) attributable to controlling interests and available to common shareholders	(5,103)		(2,290)		$ 27,036
Other comprehensive (loss) income attributable to controlling interest	48,605		11,868
Comprehensive (loss) income attributable to controlling interests	$ 43,502		$ 9,578