Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenue									$ 971,142	$ 1,748,889	$ 1,607,944
Costs and expenses:
Direct costs									947,255	1,523,194	1,179,227
Selling, general and administrative expenses									229,267	239,697	182,518
Research and development									7,718	16,704	14,327
Depreciation and amortization									217,440	276,353	108,145
Impairment expense									436,395	791,807
(Gain) loss on disposal of assets									3,075	(544)	(17)
Operating income (loss)	$ (101,602)	$ (85,553)	$ (182,437)	$ (500,416)	$ (497,432)	$ (493,338)	$ (77,350)	$ (30,202)	(870,008)	(1,098,322)	123,744
Other income (expense):
Interest expense, net									(157,465)	(82,086)	(9,840)
Other income (expense), net									9,504	8,773	598
Total other income (expense)									(147,961)	(73,313)	(9,242)
Income (loss) before reorganization items and income taxes									(1,017,969)	(1,171,635)	114,502
Reorganization items									55,330
Income tax expense (benefit)									(129,010)	(299,093)	45,679
Net income (loss)	$ (118,371)	$ (106,390)	$ (291,116)	$ (428,412)	$ (321,742)	$ (455,016)	$ (65,121)	$ (30,663)	$ (944,289)	$ (872,542)	$ 68,823
Net income (loss) per common share:
Basic (in dollars per share)	$ (1)	$ (0.90)	$ (2.46)	$ (3.65)	$ (2.75)	$ (3.89)	$ (0.56)	$ (0.51)	$ (7.98)	$ (8.48)	$ 1.28
Diluted (in dollars per share)	$ (1)	$ (0.90)	$ (2.46)	$ (3.65)	$ (2.75)	$ (3.89)	$ (0.56)	$ (0.51)	$ (7.98)	$ (8.48)	$ 1.22
Weighted average common shares outstanding:
Basic (in shares)									118,305	102,853	53,838
Diluted (in shares)									118,305	102,853	56,513