Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 21,860	$ 516
Restricted cash	10,662	0
Accrued production receivable	74,296	139,407
Trade and other receivables, net	34,788	18,318
Derivative assets	26,778	11,936
Other current assets	11,730	10,434
Total current assets	180,114	180,611
Oil and natural gas properties (using full cost accounting)
Proved properties	796,687	11,447,680
Unevaluated properties	98,656	872,910
CO2 properties	187,397	1,198,846
Pipelines	132,669	2,329,078
Other property and equipment	97,770	212,334
Less accumulated depletion, depreciation, amortization and impairment	(4,446)	(11,688,020)
Net property and equipment	1,308,733	4,372,828
Operating lease right-of-use assets	1,225	34,099
Derivative assets	1,147	0
Intangible assets, net	99,655	22,139
Other assets	86,996	82,190
Total assets	1,677,870	4,691,867
Current liabilities
Accounts payable and accrued liabilities	166,385	183,832
Oil and gas production payable	45,013	62,869
Derivative liabilities	5,739	8,346
Current maturities of long-term debt (including future interest payable of $0 and $86,054, respectively - see Note 6)	73,511	102,294
Operating lease liabilities	763	6,901
Total current liabilities	291,411	364,242
Long-term liabilities
Long-term debt, net of current portion (including future interest payable of $0 and $78,860, respectively - see Note 6)	102,456	2,232,570
Asset retirement obligations	158,757	177,108
Derivative liabilities	584	0
Deferred tax liabilities, net	3,836	410,230
Operating lease liabilities	463	41,932
Other liabilities	22,186	53,526
Total long-term liabilities	288,282	2,915,366
Stockholders' equity
Preferred stock, $.001 par value	0	0
Common stock, $.001 par value	50	508
Paid-in capital in excess of par	1,095,369	2,739,099
Treasury stock, at cost, 0 and 1,652,771 shares, respectively		(6,034)
Retained earnings (accumulated deficit)	2,758	(1,321,314)
Total stockholders' equity	1,098,177	1,412,259
Total liabilities and stockholders' equity	$ 1,677,870	$ 4,691,867