Condensed Combined Debtor-In-Possession Financial Information Condensed Combined Debtors' Statement of Cash Flows (Details) - USD ($)		3 Months Ended		9 Months Ended
	Mar. 27, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities
Net loss		$ (50,868,000)	$ (706,952,000)	$ (1,155,739,000)	$ (922,566,000)
Adjustments to reconcile net loss to net cash flow from operating activities:
Depreciation and amortization		90,606,000	112,755,000	283,652,000	333,481,000
Loss on impairment		0	595,510,000	1,119,517,000	595,510,000
Reorganization items, net				(11,531,000)	0
Gain on extinguishment of debt, net		(17,847,000)	650,000	(17,254,000)	(30,616,000)
Deferred income taxes	$ 107,600,000			6,825,000	(13,688,000)
Amortization of share-based compensation				7,352,000	10,422,000
Other costs, net				(53,179,000)	66,276,000
Changes in components of working capital:
Change in taxes receivable				29,581,000	(12,379,000)
Net changes in other operating assets and liabilities				27,442,000	(57,914,000)
Net cash provided by (used in) operating activities				236,666,000	(31,474,000)
Cash flows from investing activities
Capital expenditures				(112,603,000)	(222,587,000)
Proceeds from disposal of assets, net				1,428,000	9,430,000
Net cash used in investing activities				(111,175,000)	(213,157,000)
Cash flows from financing activities
Borrowings on credit facilities				210,000,000	455,000,000
Cash paid to settle equity awards				(1,010,000)	0
Taxes withheld on employee stock transactions				(417,000)	(2,779,000)
Net cash provided by financing activities				107,441,000	6,020,000
Net increase (decrease) in cash, cash equivalents and restricted cash				232,932,000	(238,611,000)
Cash, cash equivalents and restricted cash, beginning of period				105,924,000	375,907,000
Cash, cash equivalents and restricted cash, end of period		338,856,000	$ 137,296,000	338,856,000	$ 137,296,000
Parent Company and Subsidiaries, Debtor-in-possession
Cash flows from operating activities
Net loss		(48,327,000)		(1,185,296,000)
Adjustments to reconcile net loss to net cash flow from operating activities:
Depreciation and amortization		90,208,000		282,598,000
Loss on impairment		0		1,119,517,000
Reorganization items, net				(11,531,000)
Gain on extinguishment of debt, net		(17,847,000)		(17,254,000)
Deferred income taxes				6,737,000
Amortization of share-based compensation				7,352,000
Other costs, net				(33,290,000)
Changes in components of working capital:
Change in taxes receivable				28,130,000
Net changes in other operating assets and liabilities				24,320,000
Net changes in other operating assets and liabilities with non-debtor affiliates				(36,386,000)
Net cash provided by (used in) operating activities				184,897,000
Cash flows from investing activities
Capital expenditures				(111,601,000)
Proceeds from disposal of assets, net				1,191,000
Net cash used in investing activities				(110,410,000)
Cash flows from financing activities
Borrowings on credit facilities				210,000,000
Repayments of senior notes				(101,132,000)
Cash paid to settle equity awards				(1,010,000)
Other financing activities with non-debtor affiliates				41,037,000
Taxes withheld on employee stock transactions				(417,000)
Net cash provided by financing activities				148,478,000
Net increase (decrease) in cash, cash equivalents and restricted cash				222,965,000
Cash, cash equivalents and restricted cash, beginning of period				73,682,000
Cash, cash equivalents and restricted cash, end of period		$ 296,647,000		$ 296,647,000