UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash	$ 16,801	$ 10,364
Accounts receivable, net	35,424	30,901
Prepaid expenses and other current assets	12,297	15,572
Total current assets	64,522	56,837
Property and equipment, at cost:
Oil and natural gas properties, successful efforts method	780,757	775,167
Support equipment and facilities	142,346	142,208
Other	9,431	9,102
Accumulated depreciation, depletion and impairment	(616,578)	(609,231)
Property and equipment, net	315,956	317,246
Long-term derivative instruments	1,522	873
Restricted investments	4,623	4,623
Operating lease - long term right-of-use asset	2,394	2,500
Other long-term assets	2,541	2,680
Total assets	391,558	384,759
Current liabilities:
Accounts payable	6,364	798
Revenues payable	24,944	22,563
Accrued liabilities (see Note 13)	20,550	22,677
Short-term derivative instruments	30,391	10,824
Total current liabilities	82,249	56,862
Long-term debt (see Note 8)	255,516	260,516
Asset retirement obligations	98,201	96,725
Long-term derivative instruments	5,355	847
Operating lease liability	404	266
Other long-term liabilities	3,107	3,280
Total liabilities	444,832	418,496
Commitments and contingencies (see Note 15)
Stockholders' equity (deficit):
Preferred stock, $0.01 par value: 50,000,000 shares authorized; no shares issued and outstanding at March 31, 2021 and December 31, 2020	0	0
Warrants, 2,173,913 and 2,173,913 warrants issued and outstanding at March 31, 2021 and December 31, 2020, respectively	4,788	4,788
Common stock, $0.01 par value: 250,000,000 shares authorized; 37,969,324 and 37,663,509 shares issued and outstanding at March 31, 2021 and December 31, 2020, respectively	381	378
Additional paid-in capital	423,892	424,104
Accumulated earnings (deficit)	(482,335)	(463,007)
Total stockholders' equity (deficit)	(53,274)	(33,737)
Total liabilities and equity	$ 391,558	$ 384,759