Guarantor/Non Guarantor Condensed Consolidating Financial Statements (Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		4 Months Ended	5 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	May 31, 2020	Sep. 30, 2019
Condensed Financial Statements, Captions [Line Items]
Revenues	$ 38,998	$ 146,398	$ 50,161	$ 142,370	$ 445,809
Costs and expenses:
Operating costs	28,893	108,059	37,636	114,047	332,614
Depreciation and amortization	14,699	22,924	19,935	35,647	68,428
General and administrative	11,626	30,485	15,839	22,047	68,271
Pre-petition restructuring charges			0	16,822	0
Intercompany leasing	0	0	0	0	0
Impairment			388	17,853	1,378
Bad debt expense (recovery), net	(315)	196	(598)	1,209	(90)
Loss (gain) on dispositions of property and equipment, net	(3,829)	17	(4,289)	(989)	(2,184)
Total costs and expenses	51,074	161,681	68,911	206,636	468,417
Income (loss) from operations	(12,076)	(15,283)	(18,750)	(64,266)	(22,608)
Other income (expense):
Equity in earnings of subsidiaries	0	0	0	0	0
Interest expense	(6,253)	(10,013)	(8,468)	(12,294)	(30,003)
Reorganization Items, net	(2,522)	0	(3,666)	(21,903)	0
Loss on extinguishment of debt			0	4,215	0
Other income (expense), net	(848)	(588)	(1,078)	(3,333)	445
Total other income (expense), net	(9,623)	(10,601)	(13,212)	(41,745)	(29,558)
Income (loss) before income taxes	(21,699)	(25,884)	(31,962)	(106,011)	(52,166)
Income tax (expense) benefit	1,629	(132)	2,075	1,786	(1,909)
Net income (loss)	(20,070)	(26,016)	(29,887)	(104,225)	(54,075)
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	0	0	0	0	0
Costs and expenses:
Operating costs	0	0	0	0	0
Depreciation and amortization	0	0	0	0	0
General and administrative	(195)	(135)	(260)	(225)	(405)
Pre-petition restructuring charges				0
Intercompany leasing	0	0	0	0	0
Impairment			0	0	0
Bad debt expense (recovery), net	0	0	0	0	0
Loss (gain) on dispositions of property and equipment, net	0	0	0	0	0
Total costs and expenses	(195)	(135)	(260)	(225)	(405)
Income (loss) from operations	195	135	260	225	405
Other income (expense):
Equity in earnings of subsidiaries	7,228	(524)	13,196	236,091	(12,492)
Interest expense	0	0	0	0	0
Reorganization Items, net	0		0	0
Loss on extinguishment of debt				0
Other income (expense), net	(195)	(135)	(260)	(225)	(405)
Total other income (expense), net	7,033	(659)	12,936	235,866	(12,897)
Income (loss) before income taxes	7,228	(524)	13,196	236,091	(12,492)
Income tax (expense) benefit	0	0	0	0	0
Net income (loss)	7,228	(524)	13,196	236,091	(12,492)
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	34,937	124,781	45,272	126,442	377,127
Costs and expenses:
Operating costs	25,443	92,216	33,123	100,372	281,735
Depreciation and amortization	11,354	21,193	15,390	33,129	63,491
General and administrative	3,711	13,640	5,414	12,489	35,665
Pre-petition restructuring charges				0
Intercompany leasing	(1,215)	(1,215)	(1,620)	(2,025)	(3,645)
Impairment			388	17,853	1,378
Bad debt expense (recovery), net	(315)	196	(598)	1,209	(90)
Loss (gain) on dispositions of property and equipment, net	(3,822)	28	(4,282)	(992)	(2,077)
Total costs and expenses	35,156	126,058	47,815	162,035	376,457
Income (loss) from operations	(219)	(1,277)	(2,543)	(35,593)	670
Other income (expense):
Equity in earnings of subsidiaries	(3,639)	1,164	(5,295)	(8,594)	7,059
Interest expense	0	3	0	0	(12)
Reorganization Items, net	0		(403)	(231,420)
Loss on extinguishment of debt				0
Other income (expense), net	272	236	361	394	903
Total other income (expense), net	(3,367)	1,403	(5,337)	(239,620)	7,950
Income (loss) before income taxes	(3,586)	126	(7,880)	(275,213)	8,620
Income tax (expense) benefit	(3)	(766)	(21)	47,716	(3,187)
Net income (loss)	(3,589)	(640)	(7,901)	(227,497)	5,433
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	4,061	21,617	4,889	15,928	68,682
Costs and expenses:
Operating costs	3,450	15,843	4,513	13,675	50,879
Depreciation and amortization	3,242	1,512	4,318	2,144	4,228
General and administrative	438	1,001	584	918	2,129
Pre-petition restructuring charges				0
Intercompany leasing	1,215	1,215	1,620	2,025	3,645
Impairment			0	0	0
Bad debt expense (recovery), net	0	0	0	0	0
Loss (gain) on dispositions of property and equipment, net	7	(11)	7	0	(107)
Total costs and expenses	8,352	19,560	11,042	18,762	60,774
Income (loss) from operations	(4,291)	2,057	(6,153)	(2,834)	7,908
Other income (expense):
Equity in earnings of subsidiaries	0	0	0	0	0
Interest expense	8	4	10	21	(38)
Reorganization Items, net	0		0	(829)
Loss on extinguishment of debt				0
Other income (expense), net	(943)	(775)	(1,203)	(3,498)	(436)
Total other income (expense), net	(935)	(771)	(1,193)	(4,306)	(474)
Income (loss) before income taxes	(5,226)	1,286	(7,346)	(7,140)	7,434
Income tax (expense) benefit	1,587	(122)	2,051	(1,454)	(375)
Net income (loss)	(3,639)	1,164	(5,295)	(8,594)	7,059
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	0	0	0	0	0
Costs and expenses:
Operating costs	0	0	0	0	0
Depreciation and amortization	103	219	227	374	709
General and administrative	7,672	15,979	10,101	8,865	30,882
Pre-petition restructuring charges				16,822
Intercompany leasing	0	0	0	0	0
Impairment			0	0	0
Bad debt expense (recovery), net	0	0	0	0	0
Loss (gain) on dispositions of property and equipment, net	(14)	0	(14)	3	0
Total costs and expenses	7,761	16,198	10,314	26,064	31,591
Income (loss) from operations	(7,761)	(16,198)	(10,314)	(26,064)	(31,591)
Other income (expense):
Equity in earnings of subsidiaries	(3,589)	(640)	(7,901)	(227,497)	5,433
Interest expense	(6,261)	(10,020)	(8,478)	(12,315)	(29,953)
Reorganization Items, net	(2,522)		(3,263)	210,346
Loss on extinguishment of debt				4,215
Other income (expense), net	18	86	24	(4)	383
Total other income (expense), net	(12,354)	(10,574)	(19,618)	(33,685)	(24,137)
Income (loss) before income taxes	(20,115)	(26,772)	(29,932)	(59,749)	(55,728)
Income tax (expense) benefit	45	756	45	(44,476)	1,653
Net income (loss)	$ (20,070)	$ (26,016)	$ (29,887)	$ (104,225)	$ (54,075)