Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
	Jan. 01, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue from external customers		$ 1,638,739
Costs and expenses:
Direct costs		1,288,092
Selling, general and administrative expenses		250,871
Research and development		6,368
Depreciation and amortization		140,650
Impairment expense
(Gain) loss on disposal of assets		(31,463)
Operating income (loss)		(15,779)
Other income (expense):
Interest expense, net		(1,527)
Other income (expense), net		3
Total other income (expense)		(1,524)
Losses before reorganization items and income taxes		(17,303)
Reorganization items
Income tax benefit		(39,760)
Net income (loss)		$ 22,457
Net income (loss) per common share:
Basic (in dollars per share)		$ 0.37
Diluted (in dollars per share)		$ 0.37
Weighted average common shares outstanding:
Basic (in shares)		61,208
Diluted (in shares)		61,460
Predecessor [Member]
Revenue from external customers			$ 971,142	$ 1,748,889
Costs and expenses:
Direct costs			947,255	1,523,194
Selling, general and administrative expenses			229,267	239,697
Research and development			7,718	16,704
Depreciation and amortization			217,440	276,353
Impairment expense			436,395	791,807
(Gain) loss on disposal of assets			3,075	(544)
Operating income (loss)			(870,008)	(1,098,322)
Other income (expense):
Interest expense, net			(157,465)	(82,086)
Other income (expense), net			9,504	8,773
Total other income (expense)			(147,961)	(73,313)
Losses before reorganization items and income taxes			(1,017,969)	(1,171,635)
Reorganization items	(293,969)	$ (293,969)	55,330
Income tax benefit	(4,613)		(129,010)	(299,093)
Net income (loss)	$ 298,582		$ (944,289)	$ (872,542)
Net income (loss) per common share:
Basic (in dollars per share)	$ 2.52		$ (7.98)	$ (8.48)
Diluted (in dollars per share)	$ 2.52		$ (7.98)	$ (8.48)
Weighted average common shares outstanding:
Basic (in shares)	118,633		118,305	102,853
Diluted (in shares)	118,633		118,305	102,853