Supplemental Guarantor Information (Condensed Consolidating 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	$ 425,717			$ 573,068			$ 1,329,208	$ 1,590,934
Cost of services and rentals (exclusive of depreciation, depletion, amortization and accretion)	294,206			404,389			920,797	1,117,659
Depreciation, depletion, amortization and accretion	67,389			99,892			225,046	303,584
General and administrative expenses	62,768			68,895			208,597	214,611
Reduction in value of assets	9,571						40,952
Loss from operations	(8,217)			(108)			(66,184)	(44,920)
Other expense:
Interest income (expense), net	(24,505)			(24,952)			(74,275)	(74,733)
Other income (expense)	(3,353)			(277)			(4,476)	(4,394)
Loss from continuing operations before income taxes	(36,075)			(25,337)			(144,935)	(124,047)
Income taxes	2,366			(3,521)			12,261	(16,846)
Net loss from continuing operations	(38,441)			(21,816)			(157,196)	(107,201)
Loss from discontinued operations, net of income tax								(729)
Net loss	(38,441)	$ (71,050)	$ (47,705)	(21,816)	$ (26,390)	$ (59,724)	(157,196)	(107,930)
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	(6,459)			(4,870)			(17,587)	(22,410)
Cost of services and rentals (exclusive of depreciation, depletion, amortization and accretion)	(6,459)			(4,870)			(17,587)	(22,410)
Other expense:
Equity in losses of consolidated subsidiaries	46,109			2,687			208,539	95,278
Loss from continuing operations before income taxes	46,109			2,687			208,539	95,278
Net loss from continuing operations								95,278
Net loss	46,109			2,687			208,539	95,278
Parent [Member]
Other expense:
Equity in losses of consolidated subsidiaries	(38,441)			(21,816)			(157,196)	(107,930)
Loss from continuing operations before income taxes	(38,441)			(21,816)			(157,196)	(107,930)
Net loss from continuing operations								(107,930)
Net loss	(38,441)			(21,816)			(157,196)	(107,930)
Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Cost of services and rentals (exclusive of depreciation, depletion, amortization and accretion)	(1,373)			(793)			(8,244)	(6,382)
Depreciation, depletion, amortization and accretion	907			965			2,780	2,974
General and administrative expenses	16,581			23,959			64,319	70,721
Loss from operations	(16,115)			(24,131)			(58,855)	(67,313)
Other expense:
Interest income (expense), net	(25,911)			(26,024)			(78,195)	(77,778)
Other income (expense)	(132)			(356)			(1,207)	(608)
Equity in losses of consolidated subsidiaries	(5,124)			19,182			(49,523)	13,073
Loss from continuing operations before income taxes	(47,324)			(31,329)			(187,847)	(132,626)
Income taxes	(8,883)			(9,513)			(30,651)	(24,696)
Net loss from continuing operations								(107,930)
Net loss	(38,441)			(21,816)			(157,196)	(107,930)
Issuer [Member] | Intersegment Eliminations [Member]
Other expense:
Interest income (expense), net	(42)						(67)
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	352,158			511,510			1,108,641	1,420,368
Cost of services and rentals (exclusive of depreciation, depletion, amortization and accretion)	245,743			366,568			784,396	1,011,801
Depreciation, depletion, amortization and accretion	57,143			87,973			193,503	266,188
General and administrative expenses	35,320			34,726			109,983	109,083
Reduction in value of assets	9,571						40,952
Loss from operations	4,381			22,243			(20,193)	33,296
Other expense:
Interest income (expense), net	1,364			993			3,836	2,940
Other income (expense)	411			264			(799)	802
Equity in losses of consolidated subsidiaries	(2,544)			(53)			(1,820)	(421)
Loss from continuing operations before income taxes	3,612			23,447			(18,976)	36,617
Income taxes	9,729			5,260			34,891	7,185
Net loss from continuing operations								29,432
Net loss	(6,117)			18,187			(53,867)	29,432
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	80,018			66,428			238,154	192,976
Cost of services and rentals (exclusive of depreciation, depletion, amortization and accretion)	56,295			43,484			162,232	134,650
Depreciation, depletion, amortization and accretion	9,339			10,954			28,763	34,422
General and administrative expenses	10,867			10,210			34,295	34,807
Loss from operations	3,517			1,780			12,864	(10,903)
Other expense:
Interest income (expense), net	42			79			84	105
Other income (expense)	(3,632)			(185)			(2,470)	(4,588)
Loss from continuing operations before income taxes	(31)			1,674			10,545	(15,386)
Income taxes	1,520			732			8,021	665
Net loss from continuing operations								(16,051)
Loss from discontinued operations, net of income tax								(729)
Net loss	(1,551)			$ 942			2,524	$ (16,780)
Non-Guarantor Subsidiaries [Member] | Intersegment Eliminations [Member]
Other expense:
Interest income (expense), net	$ 42						$ 67