CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net Income (Loss)	$ 51,295	$ (228,449)
Adjustments to reconcile net loss to net cash provided by operating activities
Provision for doubtful accounts	21	283
Depreciation, depletion, and amortization	7,667	42,576
Impairment	0	209,754
Debt issuance costs amortization	36	318
(Gain) loss on derivative contracts	0	(12,467)
Cash received on settlement of derivative contracts	0	10,577
(Gain) loss on sale of assets	(19,713)	78
Stock-based compensation	799	749
Other	71	68
Changes in operating assets and liabilities	(6,945)	(10,025)
Net cash provided by (used in) operating activities	33,231	13,462
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures for property, plant and equipment	(4,389)	(6,814)
Acquisition of Assets	(3,545)	0
Purchase of other property and equipment	(59)	0
Proceeds from sale of assets	37,900	1,506
Net cash provided by (used in) investing activities	29,907	(5,308)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from borrowings	0	39,000
Repayments of borrowings	0	(37,500)
Reduction of financing lease liability	(122)	(694)
Debt issuance costs	(81)	0
Proceeds from exercise of stock options	21	0
Cash paid for tax obligations on vested stock awards	(613)	(1)
Net cash provided by (used in) financing activities	(795)	805
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS and RESTRICTED CASH	62,343	8,959
CASH, CASH EQUIVALENTS and RESTRICTED CASH, beginning of year	28,266	5,968
CASH, CASH EQUIVALENTS and RESTRICTED CASH, end of period	90,609	14,927
Supplemental Disclosure of Cash Flow Information
Cash paid for interest, net of amounts capitalized	(106)	(812)
Cash received for income taxes	0	616
Supplemental Disclosure of Noncash Investing and Financing Activities
Purchase of PP&E in accounts payable	1,260	704
Right-of-use assets obtained in exchange for financing lease obligations	363	67
Carrying value of properties exchanged	$ 0	$ 3,890