Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 68,896	$ 148,013
Revenue receivable	6,452	6,476
Joint interest billing receivable	18,560	49,374
Derivative asset	0	1,508
Other current assets	5,219	3,874
Total current assets	99,127	209,245
Oil and gas properties:
Oil and gas properties, full cost method	1,318,737	1,310,891
Unevaluated oil and gas properties	6,000	12,516
Accumulated depreciation, depletion and amortization	(1,223,051)	(1,157,455)
Oil and gas properties, net	101,686	165,952
Other property and equipment	11,257	11,229
Accumulated depreciation of other property and equipment	(10,020)	(8,737)
Total property and equipment	102,923	168,444
Other assets, net of accumulated amortization of $4,005 and $3,842, respectively	6,674	1,630
Total assets	208,724	379,319
Current liabilities:
Accounts payable to vendors	54,379	97,999
Advances from co-owners	577	16,118
Oil and gas revenue payable	29,386	18,911
Accrued interest and preferred stock dividend	9,938	12,795
Asset retirement obligation	1,496	6,015
Derivative liability	473	0
Accrued acquisition cost	0	4,409
Other accrued liabilities	3,131	2,537
Total current liabilities	99,380	158,784
10% Senior Unsecured Notes due 2017	134,766	347,008
10% Senior Secured Notes due 2021	156,524	0
Asset retirement obligation	39,986	36,541
Other long-term liabilities	2,670	53
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $.001 par value; authorized 5,000 shares; issued and outstanding 1,495 shares	1	1
Common stock, $.001 par value; authorized 150,000 shares; issued and outstanding 17,548 and 16,411 shares, respectively	18	16
Paid-in capital	293,595	290,432
Accumulated other comprehensive (loss) income	(473)	947
Accumulated deficit	(517,743)	(454,463)
Total stockholders’ equity	(224,602)	(163,067)
Total liabilities and stockholders’ equity	$ 208,724	$ 379,319