Consolidated statements of cash flows - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 21, 2017	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2016
Cash flows from operating activities
Net income (loss)		$ (118,902)	$ 33,442
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Non-cash reorganization items		0	0
Depreciation, depletion and amortization		92,599	87,888
Loss on impairment of assets		42,325	20,065
Write-off of Senior Note issuance costs, discount and premium		0	0
Derivative losses (gains)		30,802	(19,297)
Loss (gain) on sale of assets		25,996	2,582
Loss on extinguishment of debt		635	0
Other		1,573	5,470
Change in assets and liabilities:
Accounts receivable		(12,092)	(6,337)
Inventories		(489)	236
Prepaid expenses and other assets		3,245	(160)
Accounts payable and accrued liabilities		2,622	3,441
Revenue distribution payable		6,941	8,649
Deferred compensation		9,714	10,262
Net cash provided by operating activities		84,969	146,241
Cash flows from investing activities
Expenditures for property, plant, and equipment and oil and natural gas properties		(157,718)	(324,063)
Proceeds from asset dispositions		189,735	50,523
Proceeds from (payments for) derivative instruments		15,676	(18,510)
Cash in escrow		42	0
Net cash (used in) provided by investing activities		47,735	(292,050)
Cash flows from financing activities
Proceeds from long-term debt		33,000	116,000
Repayment of long-term debt		(176,407)	(243,722)
Issuance of Senior Notes		0	300,000
Proceeds from rights offering, net		0	0
Principal payments under capital lease obligations		(2,017)	(2,683)
Treasury stock purchased		0	(4,936)
Payment of other financing fees		(4,671)	(9,136)
Net cash provided by (used in) financing activities		(150,095)	155,523
Net increase (decrease) in cash and cash equivalents		(17,391)	9,714
Cash and cash equivalents at beginning of period		45,123	27,732
Cash and cash equivalents at end of period	$ 45,123	27,732	$ 37,446
Predecessor
Cash flows from operating activities
Net income (loss)	1,041,959			$ (415,720)
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Non-cash reorganization items	(1,012,090)			0
Depreciation, depletion and amortization	24,915			122,928
Loss on impairment of assets	0			282,472
Write-off of Senior Note issuance costs, discount and premium	0			16,970
Derivative losses (gains)	(48,006)			22,837
Loss (gain) on sale of assets	(206)			117
Loss on extinguishment of debt	0			0
Other	645			3,611
Change in assets and liabilities:
Accounts receivable	198			(9,243)
Inventories	466			3,576
Prepaid expenses and other assets	(497)			(1,620)
Accounts payable and accrued liabilities	8,733			25,987
Revenue distribution payable	(1,875)			509
Deferred compensation	143			(5,257)
Net cash provided by operating activities	14,385			47,167
Cash flows from investing activities
Expenditures for property, plant, and equipment and oil and natural gas properties	(31,179)			(146,296)
Proceeds from asset dispositions	1,884			1,349
Proceeds from (payments for) derivative instruments	1,285			90,590
Cash in escrow	0			48
Net cash (used in) provided by investing activities	(28,010)			(54,309)
Cash flows from financing activities
Proceeds from long-term debt	270,000			181,000
Repayment of long-term debt	(444,785)			(1,952)
Issuance of Senior Notes	0			0
Proceeds from rights offering, net	50,031			0
Principal payments under capital lease obligations	(568)			(2,491)
Treasury stock purchased	0			0
Payment of other financing fees	(2,410)			0
Net cash provided by (used in) financing activities	(127,732)			176,557
Net increase (decrease) in cash and cash equivalents	(141,357)			169,415
Cash and cash equivalents at beginning of period	186,480	$ 45,123		17,065
Cash and cash equivalents at end of period	$ 45,123			$ 186,480