Fresh Start Accounting - (Fresh Start) (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Feb. 03, 2021	Feb. 02, 2021	Jan. 01, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 391,684	$ 258,999	$ 314,974	$ 172,768	$ 172,768	$ 188,006
Restricted Cash and Cash Equivalents, Current	0	0	0	16,751	16,751	0
Accounts receivable, net					153,529
Income taxes receivable					8,976
Prepaid Expense, Current	18,614	17,299			31,630
Inventory and Other Current Assets	74,995	65,587			101,140
Assets held for sale					220,359
Total current assets	780,625	616,612			705,153
Property, plant and equipment, net	294,960	282,376			540,850
Operating lease right-of-use assets					33,918
Goodwill					138,934
Notes receivable					72,484
Restricted Cash and Cash Equivalents, Noncurrent	85,444	80,108	79,561	$ 80,179	80,179	$ 80,178
Net Balance					24,220
Total assets	1,340,993	1,191,012			1,456,804
Current liabilities:
Accounts payable	38,214	31,570			51,116
Accrued expenses	103,782	116,575			137,216
Liabilities held for sale	0	3,349			37,264
Total current liabilities	183,847	172,946			225,596
Decommissioning liability	148,652	150,901			169,515
Operating lease liability	11,338	14,634			23,555
Deferred income taxes	6,137	3,388			59,522
Other long-term liabilities	36,245	69,647			75,930
Total non-current liabilities					328,522
Liabilities subject to compromise					1,572,772
Total liabilities	380,082	408,128			554,118
Stockholders’ equity (deficit):
Common Stock $0.001 par value					200
Additional paid-in capital					902,486
Accumulated deficit	49,321	(125,699)
Total stockholders' equity	960,911	782,884	$ 741,733		902,686		$ (338,647)
Total liabilities and stockholders' equity	1,340,993	$ 1,191,012			1,456,804
Reorganization, Chapter 11, Predecessor, before Adjustment [Member]
Current assets:
Cash and cash equivalents					194,671
Accounts receivable, net					153,518
Income taxes receivable					9,146
Prepaid Expense, Current					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					401,263
Operating lease right-of-use assets					32,488
Goodwill					138,934
Notes receivable					72,484
Restricted Cash and Cash Equivalents, Noncurrent					80,179
Net Balance					52,264
Total assets	1,456,800				1,497,411
Current liabilities:
Accounts payable					51,816
Accrued expenses					126,768
Liabilities held for sale					39,642
Total current liabilities					218,226
Decommissioning liability					134,934
Operating lease liability					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	$ 2,076,100				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					(578,714)
Total liabilities and stockholders' equity					1,497,411
Reorganization Adjustments [Member]
Current assets:
Cash and cash equivalents					(21,903)
Restricted Cash and Cash Equivalents, Current					16,751
Accounts receivable, net					11
Total current assets					5,141
Net Balance					(10,080)
Total assets					(15,221)
Current liabilities:
Accounts payable					(700)
Accrued expenses					9,042
Liabilities held for sale					1,614
Total current liabilities					9,956
Decommissioning liability					0
Operating lease liability					0
Deferred income taxes					3,100
Other long-term liabilities					0
Total non-current liabilities					3,100
Liabilities subject to compromise					(1,572,772)
Total liabilities					(1,559,716)
Stockholders’ equity (deficit):
common stock $0.001 par value					(16)
Additional paid-in capital					(2,757,824)
Treasury Stock at Cost					4,290
Common Stock $0.001 par value					200
Additional paid-in capital					902,486
Accumulated other comprehensive loss, net					0
Accumulated deficit					3,395,359
Total stockholders' equity					1,544,495
Total liabilities and stockholders' equity					(15,221)
Reorganization, Chapter 11, Fresh-Start Adjustment [Member]
Current assets:
Restricted Cash and Cash Equivalents, Current					16,751
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					139,587
Operating lease right-of-use assets					1,430
Net Balance					17,964
Total assets					(25,386)
Current liabilities:
Accounts payable					0
Accrued expenses					1,406
Liabilities held for sale					(3,992)
Total current liabilities					(2,586)
Decommissioning liability					34,581
Operating lease liability					(29)
Deferred income taxes					51,569
Other long-term liabilities					(45,826)
Total non-current liabilities					40,295
Total liabilities					37,709
Stockholders’ equity (deficit):
Common Stock $0.001 par value
Additional paid-in capital					0
Accumulated other comprehensive loss, net					67,532
Accumulated deficit					(130,627)
Total stockholders' equity					(63,095)
Total liabilities and stockholders' equity					$ (25,386)