Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues:
Other	$ 1	$ 16	$ 37	$ 31
	30,916	13,152	71,546	31,954
Operating costs and expenses
Lease operating	5,730	3,421	10,299	7,539
Production and ad valorem taxes	2,485	1,158	5,598	2,778
Depreciation, depletion and amortization	8,705	4,415	18,835	9,789
General and administrative (including stock-based compensation of $879, $979, $1,466 and $1,749, respectively)	3,065	2,898	5,793	5,635
	19,985	11,892	40,525	25,741
Operating income	10,931	1,260	31,021	6,213
Other (income) expense:
Interest income	(1)	(1)	(1)	(1)
Interest expense	1,627	501	2,956	1,008
Amortization of deferred financing fees	111	117	207	254
Loss (gain) on derivative contracts	19,763	(6,450)	27,646	(15,831)
Gain on sale of non-oil and gas assets	(15)	(102)	(12)	(102)
	21,485	(5,935)	30,796	(14,672)
(Loss) income before income tax	(10,554)	7,195	225	20,885
Income tax (expense) benefit	0	0	0	0
Net (loss) income	$ (10,554)	$ 7,195	$ 225	$ 20,885
Net (loss) income per common share - basic (in dollars per share)	$ (0.06)	$ 0.04	$ 0	$ 0.13
Net (loss) income per common share - diluted (in dollars per share)	$ (0.06)	$ 0.04	$ 0	$ 0.13
Weighted average shares outstanding
Basic (in shares)	165,162	162,357	164,812	158,259
Diluted (in shares)	165,162	163,805	167,715	159,942
Oil Revenues [Member]
Revenues:
Revenues	$ 27,472	$ 11,313	$ 63,466	$ 26,814
Gas Revenues [Member]
Revenues:
Revenues	1,608	1,063	3,985	3,045
Natural Gas Liquids Revenues [Member]
Revenues:
Revenues	1,835	760	4,058	2,064
Oil and Gas [Member]
Revenues:
Revenues	$ 30,915	$ 13,136	$ 71,509	$ 31,923