Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 13,650	$ 6,313
Equity securities		47,082
Accounts receivable:
Oil, natural gas and natural gas liquids revenues	29,252	40,176
Other	1,355	4,496
Derivative asset	14,137	15,452
Other current assets	944	2,314
Total current assets	59,338	115,833
Oil and natural gas properties, net of accumulated depreciation, depletion and amortization; June 30, 2019, $7,175; December 31, 2018, $12,950	159,388	405,688
Assets held for sale	87,260
Long–term derivative asset	4,781	8,499
Other assets	7,112	4,474
Total assets	317,879	534,494
Current liabilities:
Accounts payable and accrued liabilities	25,095	26,146
Derivative liability		1,165
Other current liabilities	731
Total current liabilities	25,826	27,311
Asset retirement obligations	102,108	117,529
Long–term debt, net		115,000
Liabilities held for sale	10,618
Other long–term liabilities	1,804	1,036
Commitments and contingencies (Note 11)
Mezzanine equity	135	79
Stockholders’ equity:
Common stock – $0.01 par value; 65,000,000 shares authorized; 10,141,512 shares issued and 10,117,472 shares outstanding as of June 30, 2019; 10,054,816 shares issued and 10,042,468 shares outstanding as of December 31, 2018	101	100
Additional paid-in capital	250,414	249,717
Treasury stock at cost – 24,040 shares at June 30, 2019; 12,348 shares at December 31, 2018	(414)	(247)
Retained earnings (accumulated deficit)	(72,713)	23,969
Total stockholders’ equity	177,388	273,539
Total liabilities and equity	$ 317,879	$ 534,494