Fresh Start Accounting (Fresh Start) (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Feb. 02, 2021
Current assets:
Cash and cash equivalents		$ 194,671
Accounts receivable, net of allowance for doubtful accounts		153,518
Income taxes receivable		9,146
Prepaid expenses		31,630
Inventory and other current assets		90,073
Assets held for sale		240,761
Total current assets		719,799
Property, plant and equipment, net of accumulated depreciation and depletion		401,263
Operating lease right-of-use assets		32,488
Goodwill		138,934
Notes receivable		72,484
Restricted cash - non-current		80,179
Intangible and other long-term assets, net of accumulated amortization		52,264
Total assets	$ 1,456,800	1,497,411
Preconfirmation, Current Liabilities [Abstract]
Accounts payable		51,816
Accrued expenses		126,768
Liabilities held for sale		39,642
Total current liabilities		218,226
Decommissioning liabilities		134,934
Operating lease liabilities		23,584
Deferred income taxes		4,853
Other long-term liabilities		121,756
Total non-current liabilities		285,127
Liabilities subject to compromise		1,572,772
Total liabilities not subject to compromise		2,076,125
Stockholders’ equity (deficit):
common stock $0.001 par value		16
Additional paid-in capital		2,757,824
Treasury stock at cost		4,290
Accumulated other comprehensive loss, net		(67,532)
Accumulated deficit		(3,264,732)
Total stockholders’ equity (deficit)		(578,714)
Total liabilities and stockholders’ equity (deficit)		1,497,411
Fresh-Start Adjustment, Increase (Decrease), Assets [Abstract]
Restricted cash - current		16,751
Fresh-Start Adjustment, Increase (Decrease), Liabilities [Abstract]
Liabilities subject to compromise		1,572,772
Postconfirmation, Assets [Abstract]
Cash and cash equivalents		172,768
Restricted cash - current		16,751
Accounts receivable, net of allowance for doubtful accounts		153,529
Income taxes receivable		8,976
Prepaid expenses		31,630
Inventory and other current assets		101,140
Assets held for sale		220,359
Total current assets		705,153
Property, plant and equipment, net of accumulated depreciation and depletion		540,850
Operating lease right-of-use assets		33,918
Notes receivable		72,484
Restricted cash - non-current		80,179
Intangible and other long-term assets, net of accumulated amortization		24,220
Total assets		1,456,804
Postconfirmation, Liabilities [Abstract]
Postconfirmation, Accounts Payable		51,116
Postconfirmation, Accrued Liabilities		137,216
Postconfirmation, Disposal Group, Including Discontinued Operation, Liabilities		37,264
Postconfirmation, Current Liabilities, Total		225,596
Postconfirmation, Asset Retirement Obligations, Noncurrent		169,515
Postconfirmation, Operating Lease, Liability, Noncurrent		23,555
Postconfirmation, Deferred Income Tax Liabilities, Noncurrent		59,522
Postconfirmation, Noncurrent Other Obligations		75,930
Total non-current liabilities		328,522
Postconfirmation, Liabilities, Total	$ 2,076,100	554,118
Postconfirmation, Stockholders' Equity [Abstract]
common stock $0.001 par value		200
Additional paid-in capital		902,486
Total stockholders’ equity (deficit)		902,686
Total liabilities and stockholders’ equity (deficit)		1,456,804
Reorganization Adjustments [Member]
Fresh-Start Adjustment, Increase (Decrease), Assets [Abstract]
Cash and cash equivalents		(21,903)
Restricted cash - current		16,751
Accounts receivable, net of allowance for doubtful accounts		11
Total current assets		(5,141)
Intangible and other long-term assets, net of accumulated amortization		(10,080)
Total assets		(15,221)
Fresh-Start Adjustment, Increase (Decrease), Liabilities [Abstract]
Accounts payable		(700)
Accrued expenses		9,042
Liabilities held for sale		1,614
Total current liabilities		9,956
Deferred income taxes		3,100
Total non-current liabilities		3,100
Liabilities subject to compromise		(1,572,772)
Total liabilities not subject to compromise		(1,559,716)
Fresh-Start Adjustment, Increase (Decrease), Stockholders' Equity [Abstract]
common stock $0.001 par value		(16)
common stock $0.001 par value		200
Additional paid-in capital		(2,757,824)
Additional paid-in capital		902,486
Treasury stock at cost		(4,290)
Accumulated deficit		3,395,359
Total stockholders’ equity (deficit)		1,544,495
Total liabilities and stockholders’ equity (deficit)		(15,221)
Fresh Start Accounting Adjustments [Member]
Fresh-Start Adjustment, Increase (Decrease), Assets [Abstract]
Income taxes receivable		(170)
Inventory and other current assets		11,067
Assets held for sale		(20,402)
Total current assets		(9,505)
Property, plant and equipment, net of accumulated depreciation and depletion		139,587
Operating lease right-of-use assets		1,430
Goodwill		(138,934)
Intangible and other long-term assets, net of accumulated amortization		(17,964)
Total assets		(25,386)
Fresh-Start Adjustment, Increase (Decrease), Liabilities [Abstract]
Accrued expenses		1,406
Liabilities held for sale		(3,992)
Total current liabilities		(2,586)
Decommissioning liabilities		34,581
Operating lease liabilities		(29)
Deferred income taxes		51,569
Other long-term liabilities		(45,826)
Total non-current liabilities		40,295
Total liabilities not subject to compromise		37,709
Fresh-Start Adjustment, Increase (Decrease), Stockholders' Equity [Abstract]
Accumulated other comprehensive loss, net		67,532
Accumulated deficit		(130,627)
Total stockholders’ equity (deficit)		(63,095)
Total liabilities and stockholders’ equity (deficit)		$ (25,386)