CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Cash Flows [Abstract]
Net increase (decrease) in cash and cash equivalents	$ (10,066)	$ 6,847	$ 4,256
Cash and cash equivalents - beginning of period	17,864	11,017	6,761
Cash and cash equivalents - end of period	7,798	17,864	11,017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	70,589	224,785	32,662
Adjustments to reconcile net income to net cash provided by operating activities:
Non-cash reorganization items	0	(3,322)	0
Depreciation, depletion and amortization	174,569	127,961	48,649
Derivative contracts:
Net (gains) losses	68,131	(37,427)	17,819
Cash settlements, net	(4,136)	(48,291)	(3,511)
Deferred income tax expense (benefit)	3,373	2,994	(4,943)
Loss (gain) on sales of assets, net	(5)	177	36
Non-cash interest expense	3,354	3,416	2,122
Share-based compensation (equity-classified)	4,082	4,618	3,809
Other, net	52	44	61
Changes in operating assets and liabilities:
Accounts receivable, net	(5,079)	(23,674)	(43,318)
Accounts payable and accrued expenses	4,690	21,109	28,542
Other assets and liabilities	574	(258)	(218)
Net Cash Provided by (Used in) Operating Activities	320,194	272,132	81,710
CASH FLOWS FROM INVESTING ACTIVITIES
Acquisitions, net	(6,516)	(85,387)	(200,849)
Capital expenditures	(362,743)	(430,592)	(115,687)
Proceeds from sales of assets, net	215	7,683	869
Net cash used in investing activities	(369,044)	(508,296)	(315,667)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from credit facility borrowings	76,400	244,000	59,000
Repayment of credit facility borrowings	(35,000)	0	(7,000)
Proceeds from second lien note	0	0	196,000
Debt issuance costs paid	(2,616)	(989)	(9,787)
Proceeds received from rights offering, net	0	0	55
Other, net	0	0	(55)
Net cash provided by financing activities	38,784	243,011	238,213
Cash paid for:
Interest, net of amounts capitalized	32,398	22,599	4,102
Income taxes, net of (refunds)	(2,471)	0	0
Reorganization items, net	79	540	954
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Increase (Decrease) in Accounts Receivable, Acquisitions	(152)	(27,107)	(2,583)
Increase (Decrease) in Other Assets, Acquisitions	0	(743)	3,201
Increase (Decrease) in Accrued Liabilities, Acquisitions	(540)	(11,182)	(2,507)
Capital Expenditures, Period Increase (Decrease)	(3,602)	44	19,910
Increase (Decrease) in ARO, Acquisitions	$ 83	$ 385	$ 494