Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
REVENUES
Revenues	$ 155,540	$ 103,622	$ 297,037	$ 213,814
OPERATING EXPENSES
Lease operating	10,141	7,324	17,666	16,714
Production and ad valorem taxes	4,009	2,178	6,857	4,623
Brokered natural gas and marketing expense	11,983	430	21,443	477
Depreciation, depletion, amortization and accretion	38,597	32,922	68,494	64,233
Exploration	15,193	9,620	31,981	24,898
General and administrative	13,564	10,697	42,494	20,454
(Gain) loss on sale of assets	1	(1,553)	2	(1,820)
Other expense	12		38
Total operating expenses	145,370	92,989	282,013	188,639
OPERATING INCOME	10,170	10,633	15,024	25,175
OTHER INCOME (EXPENSE)
Gain (loss) on derivative instruments	29,738	(16,577)	24,808	(20,792)
Interest expense, net	(15,109)	(13,092)	(28,949)	(26,043)
Other income	8		8
Total other income (expense), net	14,637	(29,669)	(4,133)	(46,835)
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	24,807	(19,036)	10,891	(21,660)
INCOME (LOSS) FROM CONTINUING OPERATIONS	24,807	(19,036)	10,891	(21,660)
Income from discontinued operations, net of income tax	2,705		2,523
NET INCOME (LOSS)	$ 27,512	$ (19,036)	$ 13,414	$ (21,660)
Basic:
Weighted average common stock outstanding	35,678	20,129	30,645	19,848
Income (loss) from continuing operations	$ 0.69	$ (0.95)	$ 0.36	$ (1.09)
Income from discontinued operations	0.08		0.08
Net income (loss)	$ 0.77	$ (0.95)	$ 0.44	$ (1.09)
Diluted:
Weighted average common stock outstanding	35,826	20,129	30,830	19,848
Income (loss) from continuing operations	$ 0.69	$ (0.95)	$ 0.36	$ (1.09)
Income from discontinued operations	0.08		0.08
Net income (loss)	$ 0.77	$ (0.95)	$ 0.44	$ (1.09)
Oil and Gas [Member]
REVENUES
Revenues	$ 143,429	$ 103,257	$ 275,257	$ 213,441
Brokered Natural Gas and Marketing Revenue [Member]
REVENUES
Revenues	11,989	365	21,519	373
Other Revenue [Member]
REVENUES
Revenues	122		261
Natural Gas, Gathering, Transportation, Marketing and Processing [Member]
OPERATING EXPENSES
Transportation, gathering and compression	$ 51,870	$ 31,371	$ 93,038	$ 59,060