STATEMENTS OF CONSOLIDATED CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net income (loss)	$ (464,030)	$ (35,197)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion and amortization	40,268	55,843
Impairment expense	476,936	2,246
(Gain) loss on derivative instruments	(56,628)	6,476
Cash settlements (paid) received on expired derivative instruments	61,135	4,344
Cash settlements (paid) received on terminated derivative instruments	17,977	0
Bad debt expense	294	301
Amortization and write-off of deferred financing costs	3,272	1,174
Accretion of asset retirement obligations	6,206	5,559
Share-based compensation (see Note 12)	(112)	4,530
Settlement of asset retirement obligations	(327)	(259)
Write-off of other property, plant & equipment	0	1,325
Other	0	(8)
Changes in operating assets and liabilities:
Accounts receivable	1,950	10,701
Prepaid expenses and other assets	(2,334)	713
Payables and accrued liabilities	(9,803)	(13,592)
Other	(474)	3,127
Net cash provided by operating activities	74,330	47,283
Cash flows from investing activities:
Cash acquired from the Merger	0	19,250
Additions to oil and gas properties	(34,833)	(72,709)
Additions to other property and equipment	(1,057)	(1,081)
Additions to restricted investments	0	(155)
Withdrawals of restricted investments	0	90,000
Other	0	10
Net cash provided by (used in) investing activities	(35,890)	35,315
Cash flows from financing activities:
Advances on revolving credit facilities	25,000	125,000
Payments on revolving credit facilities	(55,000)	(134,000)
Proceeds from the paycheck protection program	5,516	0
Deferred financing costs	(115)	(882)
Dividends to stockholders	(3,786)	(15,889)
Common stock repurchased and retired under the share repurchase program	0	(26,203)
Treasury stock acquired and retired	0	(3,340)
Costs incurred in conjunction with tender offer	0	(107)
Restricted shares returned to plan and retired	(51)	(406)
Other	35	84
Net cash provided by (used in) financing activities	(28,401)	(132,302)
Net change in cash, cash equivalents and restricted cash	10,039	(49,704)
Cash, cash equivalents and restricted cash, beginning of period	325	50,029
Cash, cash equivalents and restricted cash, end of period	10,364	325
Midstates [Member]
Cash flows from financing activities:
Payments on revolving credit facilities	$ 0	$ (76,559)