Guarantor/Non Guarantor Condensed Consolidating Financial Statements (Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Condensed Financial Statements, Captions [Line Items]
Revenues	$ 146,398			$ 149,332			$ 445,809	$ 448,592
Costs and expenses:
Operating costs	108,059			108,961			332,614	325,924
Depreciation	22,924			23,501			68,428	70,535
General and administrative	30,485			14,043			68,271	58,066
Bad debt expense (recovery), net	196			111			(90)	(311)
Impairment	0			239			1,378	2,607
Loss (gain) on dispositions of property and equipment, net	17			(1,861)			(2,184)	(2,922)
Intercompany leasing	0			0			0	0
Total costs and expenses	161,681			144,994			468,417	453,899
Income (loss) from operations	(15,283)			4,338			(22,608)	(5,307)
Other income (expense):
Equity in earnings of subsidiaries	0			0			0	0
Interest expense, net of interest capitalized	(10,013)			(9,811)			(30,003)	(28,966)
Other income (expense), net	(588)			498			445	1,046
Total other income (expense), net	(10,601)			(9,313)			(29,558)	(27,920)
Income (loss) before income taxes	(25,884)			(4,975)			(52,166)	(33,227)
Income tax (expense) benefit	(132)			(258)			(1,909)	(1,297)
Net income (loss)	(26,016)	$ (12,944)	$ (15,115)	(5,233)	$ (18,152)	$ (11,139)	(54,075)	(34,524)
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	0			0			0	0
Costs and expenses:
Operating costs	0			0			0	0
Depreciation	0			0			0	0
General and administrative	(135)			(105)			(405)	(315)
Bad debt expense (recovery), net	0			0			0	0
Impairment				0			0	0
Loss (gain) on dispositions of property and equipment, net	0			0			0	0
Intercompany leasing	0			0			0	0
Total costs and expenses	(135)			(105)			(405)	(315)
Income (loss) from operations	135			105			405	315
Other income (expense):
Equity in earnings of subsidiaries	(524)			(5,629)			(12,492)	(13,386)
Interest expense, net of interest capitalized	0			0			0	0
Other income (expense), net	(135)			(105)			(405)	(315)
Total other income (expense), net	(659)			(5,734)			(12,897)	(13,701)
Income (loss) before income taxes	(524)			(5,629)			(12,492)	(13,386)
Income tax (expense) benefit	0			0			0	0
Net income (loss)	(524)			(5,629)			(12,492)	(13,386)
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	124,781			126,202			377,127	386,077
Costs and expenses:
Operating costs	92,216			89,950			281,735	276,893
Depreciation	21,193			21,769			63,491	65,498
General and administrative	13,640			11,152			35,665	37,781
Bad debt expense (recovery), net	196			111			(90)	(311)
Impairment				239			1,378	2,607
Loss (gain) on dispositions of property and equipment, net	28			(1,856)			(2,077)	(2,890)
Intercompany leasing	(1,215)			(1,215)			(3,645)	(3,645)
Total costs and expenses	126,058			120,150			376,457	375,933
Income (loss) from operations	(1,277)			6,052			670	10,144
Other income (expense):
Equity in earnings of subsidiaries	1,164			618			7,059	3,305
Interest expense, net of interest capitalized	3			(12)			(12)	(14)
Other income (expense), net	236			222			903	664
Total other income (expense), net	1,403			828			7,950	3,955
Income (loss) before income taxes	126			6,880			8,620	14,099
Income tax (expense) benefit	(766)			(1,869)			(3,187)	(4,018)
Net income (loss)	(640)			5,011			5,433	10,081
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	21,617			23,130			68,682	62,515
Costs and expenses:
Operating costs	15,843			19,011			50,879	49,031
Depreciation	1,512			1,463			4,228	4,211
General and administrative	1,001			736			2,129	1,972
Bad debt expense (recovery), net	0			0			0	0
Impairment				0			0	0
Loss (gain) on dispositions of property and equipment, net	(11)			(5)			(107)	(32)
Intercompany leasing	1,215			1,215			3,645	3,645
Total costs and expenses	19,560			22,420			60,774	58,827
Income (loss) from operations	2,057			710			7,908	3,688
Other income (expense):
Equity in earnings of subsidiaries	0			0			0	0
Interest expense, net of interest capitalized	4			3			(38)	11
Other income (expense), net	(775)			137			(436)	292
Total other income (expense), net	(771)			140			(474)	303
Income (loss) before income taxes	1,286			850			7,434	3,991
Income tax (expense) benefit	(122)			(232)			(375)	(686)
Net income (loss)	1,164			618			7,059	3,305
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	0			0			0	0
Costs and expenses:
Operating costs	0			0			0	0
Depreciation	219			269			709	826
General and administrative	15,979			2,260			30,882	18,628
Bad debt expense (recovery), net	0			0			0	0
Impairment				0			0	0
Loss (gain) on dispositions of property and equipment, net	0			0			0	0
Intercompany leasing	0			0			0	0
Total costs and expenses	16,198			2,529			31,591	19,454
Income (loss) from operations	(16,198)			(2,529)			(31,591)	(19,454)
Other income (expense):
Equity in earnings of subsidiaries	(640)			5,011			5,433	10,081
Interest expense, net of interest capitalized	(10,020)			(9,802)			(29,953)	(28,963)
Other income (expense), net	86			244			383	405
Total other income (expense), net	(10,574)			(4,547)			(24,137)	(18,477)
Income (loss) before income taxes	(26,772)			(7,076)			(55,728)	(37,931)
Income tax (expense) benefit	756			1,843			1,653	3,407
Net income (loss)	$ (26,016)			$ (5,233)			$ (54,075)	$ (34,524)