Supplemental Guarantor Information (Condensed Consolidating Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Condensed Financial Statements, Captions [Line Items]
Revenues	$ 535,548	$ 470,068	$ 1,017,866	$ 871,004
Cost of services and rentals (exclusive of depreciation, depletion, amortization and accretion)	369,810	351,802	713,270	673,788
Depreciation, depletion, amortization and accretion	97,973	108,119	203,692	222,400
General and administrative expenses	69,896	76,708	145,716	152,201
Loss from operations	(2,131)	(66,561)	(44,812)	(177,385)
Other income (expense):
Interest expense, net	(24,894)	(23,333)	(49,781)	(47,583)
Other income (expense)	(2,382)	(2,156)	(4,117)	(1,507)
Loss from continuing operations before income taxes	(29,407)	(92,050)	(98,710)	(226,475)
Income taxes	(3,970)	(30,011)	(13,325)	(74,775)
Net loss from continuing operations	(25,437)	(62,039)	(85,385)	(151,700)
Loss from discontinued operations, net of income tax	(953)	(1,767)	(729)	(3,765)
Net loss	(26,390)	(63,806)	(86,114)	(155,465)
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	(11,465)	(2,571)	(17,540)	(7,683)
Cost of services and rentals (exclusive of depreciation, depletion, amortization and accretion)	(11,465)	(2,571)	(17,540)	(7,683)
Other income (expense):
Equity in losses of consolidated subsidiaries	15,229	88,499	92,591	234,780
Loss from continuing operations before income taxes	15,229	88,499	92,591	234,780
Net loss from continuing operations	15,229	88,499	92,591	234,780
Net loss	15,229	88,499	92,591	234,780
Parent [Member]
Other income (expense):
Equity in losses of consolidated subsidiaries	(26,390)	(63,806)	(86,114)	(155,465)
Loss from continuing operations before income taxes	(26,390)	(63,806)	(86,114)	(155,465)
Net loss from continuing operations	(26,390)	(63,806)	(86,114)	(155,465)
Net loss	(26,390)	(63,806)	(86,114)	(155,465)
Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Cost of services and rentals (exclusive of depreciation, depletion, amortization and accretion)	(2,963)	1,500	(5,589)	2,260
Depreciation, depletion, amortization and accretion	990	1,035	2,009	2,081
General and administrative expenses	21,098	25,948	46,762	51,883
Loss from operations	(19,125)	(28,483)	(43,182)	(56,224)
Other income (expense):
Interest expense, net	(25,884)	(24,370)	(51,754)	(49,611)
Other income (expense)	(186)	(311)	(252)	(722)
Equity in losses of consolidated subsidiaries	11,361	(24,545)	(6,109)	(79,107)
Loss from continuing operations before income taxes	(33,834)	(77,709)	(101,297)	(185,664)
Income taxes	(7,444)	(13,903)	(15,183)	(30,199)
Net loss from continuing operations	(26,390)	(63,806)	(86,114)	(155,465)
Net loss	(26,390)	(63,806)	(86,114)	(155,465)
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	473,724	416,328	908,858	770,188
Cost of services and rentals (exclusive of depreciation, depletion, amortization and accretion)	334,169	311,009	645,233	595,969
Depreciation, depletion, amortization and accretion	85,501	94,031	178,215	194,599
General and administrative expenses	35,668	37,732	74,357	74,876
Loss from operations	18,386	(26,444)	11,053	(95,256)
Other income (expense):
Interest expense, net	980	957	1,947	1,759
Other income (expense)	264	206	538	447
Equity in losses of consolidated subsidiaries	(200)	(148)	(368)	(208)
Loss from continuing operations before income taxes	19,430	(25,429)	13,170	(93,258)
Income taxes	3,001	(15,278)	1,925	(44,246)
Net loss from continuing operations	16,429	(10,151)	11,245	(49,012)
Net loss	16,429	(10,151)	11,245	(49,012)
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	73,289	56,311	126,548	108,499
Cost of services and rentals (exclusive of depreciation, depletion, amortization and accretion)	50,069	41,864	91,166	83,242
Depreciation, depletion, amortization and accretion	11,482	13,053	23,468	25,720
General and administrative expenses	13,130	13,028	24,597	25,442
Loss from operations	(1,392)	(11,634)	(12,683)	(25,905)
Other income (expense):
Interest expense, net	10	80	26	269
Other income (expense)	(2,460)	(2,051)	(4,403)	(1,232)
Loss from continuing operations before income taxes	(3,842)	(13,605)	(17,060)	(26,868)
Income taxes	473	(830)	(67)	(330)
Net loss from continuing operations	(4,315)	(12,775)	(16,993)	(26,538)
Loss from discontinued operations, net of income tax	(953)	(1,767)	(729)	(3,765)
Net loss	$ (5,268)	$ (14,542)	$ (17,722)	$ (30,303)