Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash	$ 10,200	$ 23,264
Accounts receivable:
Oil, natural gas, and natural gas liquids revenues	13,998	13,529
Joint interest billings and other, net of allowance of $163 and $170 at December 31, 2016 and 2015, respectively	2,698	4,924
Derivative asset		3,694
Prepaid expenses and other current assets	446	498
Total current assets	27,342	45,909
Oil and gas properties, successful efforts method:
Proved properties	363,072	283,644
Unproved properties	51,723	34,609
Total oil and gas properties	414,795	318,253
Accumulated depreciation, depletion and amortization	(145,393)	(119,920)
Net oil and gas properties	269,402	198,333
Other noncurrent assets:
Goodwill	17,620	17,532
Office and other equipment, net of accumulated depreciation of $1,600 and $1,028 at December 31, 2016 and 2015, respectively	1,479	1,934
Other noncurrent assets	669	1,236
TOTAL ASSETS	316,512	264,944
Current liabilities:
Accounts payable	11,927	11,580
Revenues and royalties payable	10,769	8,576
Accrued expenses	5,392	12,975
Derivative liability	4,595
Advances	4,542	15,447
Current portion of long-term debt	1,604
Total current liabilities	38,829	48,578
Noncurrent liabilities:
Long-term debt	12,693	11,191
Asset retirement obligation	6,013	5,075
Derivative liability	1,575
Deferred tax liability	15,776
Other noncurrent liabilities	169	227
Total noncurrent liabilities	36,226	16,493
Commitments and Contingencies (Note 14)
Equity:
Preferred stock, $0.001 par value, 20,000,000 shares authorized; none issued or outstanding
Common stock, $0.001 par value, 100,000,000 shares authorized; 22,289,177 issued and 22,273,820 outstanding at December 31, 2016 and 13,835,128 issued and 13,819,771 outstanding at December 31, 2015	23	14
Additional paid-in capital	454,202	358,086
Accumulated deficit	(212,308)	(157,767)
Treasury stock, 15,357 shares at December 31, 2016 and 2015, respectively	(460)	(460)
Total equity	241,457	199,873
TOTAL LIABILITIES AND EQUITY	$ 316,512	$ 264,944