Chapter 11 Proceeds, Liquidity, and Ability to Continue as a Going Concern (DIP Condensed Combined Statements of Cash Flows (Unaudited)) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net loss	$ (215,565)	$ (8,017)	$ (1,019,239)	$ (10,299)
Depreciation, depletion, and amortization	35,960	66,292	97,577	128,418
Impairments	109,318	0	851,242	0
Loss on abandonment of assets	0	0	17,554	0
Amortization of debt issuance costs and debt discount			1,079	1,115
Loss on derivatives			6,454	(995)
Cash receipts on derivatives settled	1,243	(2,658)	691	(5,314)
Loss on disposition of assets			1,267	1,193
Write-off of debt issuance costs			(2,426)	0
Deferred tax benefit	(6,455)	(1,874)	(8,963)	(2,318)
Employee stock compensation plans			4,179	11,187
Bad debt expense			1,923	0
ARO liability accretion			1,169	1,168
Noncash reorganization items			7,027	0
Other, net			11,493	(51)
Accounts receivable			26,587	26,939
Material and supplies			43	(43)
Prepaid expenses and other			(2,703)	(377)
Accounts payable			(22,876)	(30,374)
Accrued liabilities			48,244	(1,245)
Net cash provided by operating activities			26,467	127,501
Capital expenditures			(23,804)	(246,638)
Producing properties and other acquisitions			(210)	(3,313)
Proceeds from disposition of property and equipment			4,497	7,340
Net cash used in investing activities			(19,517)	(242,611)
Borrowings under line of credit, including borrowings under DIP credit facility			79,400	271,200
Payments under line of credit			(38,100)	(160,200)
DIP financing costs			990	0
Employee taxes paid by withholding shares			43	4,073
Bank overdrafts			(8,733)	5,298
Net cash provided by financing activities			29,473	109,327
Net increase (decrease) in cash and cash equivalents			36,423	(5,783)
Cash and cash equivalents, beginning of period			571	6,452
Cash and cash equivalents, end of period	36,994	$ 669	36,994	$ 669
Debtor-in-possession [Member]
Net loss	(215,567)		(1,019,239)
Depreciation, depletion, and amortization	25,612		74,956
Impairments	109,318		787,280
Loss on abandonment of assets	0		17,554
Amortization of debt issuance costs and debt discount			1,079
Equity investment in non-debtor subsidiairies			66,086
Loss on derivatives			6,454
Cash receipts on derivatives settled			691
Loss on disposition of assets			1,282
Write-off of debt issuance costs			(2,426)
Deferred tax benefit			(8,963)
Employee stock compensation plans			4,179
Bad debt expense			1,923
ARO liability accretion			1,169
Noncash reorganization items			7,027
Other, net			11,621
Accounts receivable			26,609
Material and supplies			43
Prepaid expenses and other			(3,158)
Accounts payable			(20,958)
Accrued liabilities			49,661
Net cash provided by operating activities			6,340
Capital expenditures			(14,188)
Producing properties and other acquisitions			(210)
Proceeds from disposition of property and equipment			4,422
Net cash used in investing activities			(9,976)
Borrowings under line of credit, including borrowings under DIP credit facility			47,300
Payments under line of credit			(23,500)
DIP financing costs			990
Intercompany borrowings			781
Employee taxes paid by withholding shares			43
Bank overdrafts			7,269
Net cash provided by financing activities			16,279
Net increase (decrease) in cash and cash equivalents			12,643
Cash and cash equivalents, beginning of period			571
Cash and cash equivalents, end of period	$ 13,214		$ 13,214