CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
CURRENT ASSETS:
Cash and cash equivalents	$ 8,428	$ 68,498
Accounts receivable:
Oil and gas sales	30,467	32,455
Joint interest billing	3,691	3,297
Other	259	166
Commodity derivative contracts		762
Other current assets	3,124	1,510
Total current assets	45,969	106,688
Oil and gas properties, on the basis of full-cost accounting
Proved properties	798,593	765,308
Unproved properties not being amortized	7,142	7,065
Other property and equipment	6,502	6,508
Less accumulated depreciation, depletion, amortization and impairment	(219,590)	(204,419)
Net property and equipment	592,647	574,462
OTHER NONCURRENT ASSETS	7,006	6,978
TOTAL	645,622	688,128
CURRENT LIABILITIES:
Accounts payable	6,652	11,547
Accrued liabilities	45,533	42,842
Commodity derivative contracts	6,062	3,433
Total current liabilities	58,247	57,822
LONG-TERM LIABILITIES:
Asset retirement obligations	15,853	15,506
Commodity derivative contracts	950	562
Long-term debt	78,059	128,059
Other long-term liabilities	585	592
Total long-term liabilities	95,447	144,719
COMMITMENTS AND CONTINGENCIES (Note 14)
STOCKHOLDERS' EQUITY:
Preferred stock, $0.01 par value, 50,000,000 shares authorized; no shares issued or outstanding at March 31, 2018 and December 31, 2017
Warrants, 6,625,554 warrants outstanding at March 31, 2018 and December 31,2017	37,329	37,329
Common stock, $0.01 par value, 250,000,000 shares authorized; 25,383,854 shares issued and 25,255,485 shares outstanding at March 31, 2018; 25,272,969 shares issued and 25,173,346 shares outstanding at December 31, 2017	254	253
Treasury stock	(2,062)	(1,603)
Additional paid-in-capital	527,550	524,755
Retained deficit	(71,143)	(75,147)
Total stockholders' equity	491,928	485,587
TOTAL	$ 645,622	$ 688,128