Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) (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
Natural gas, oil and natural gas liquids sales	$ 103,622	$ 86,191	$ 213,814	$ 188,053
Brokered natural gas and marketing revenue	365	(3)	373	2,428
Total revenues	103,622	86,191	213,814	188,053
OPERATING EXPENSES
Lease operating	7,324	4,568	16,714	6,911
Production and ad valorem taxes	2,178	2,033	4,623	3,964
Brokered natural gas and marketing expense	430	6	477	2,466
Depreciation, depletion and amortization	32,760	25,152	63,916	51,341
Exploration	9,620	8,997	24,898	20,577
General and administrative	10,697	10,730	20,454	20,862
Accretion of asset retirement obligations	162	128	317	252
(Gain) loss on sale of assets	(1,553)	6	(1,820)	1
Total operating expenses	92,989	80,589	188,639	168,220
OPERATING INCOME (LOSS)	10,633	5,602	25,175	19,833
OTHER INCOME (EXPENSE)
Gain (loss) on derivative instruments	(16,577)	18,177	(20,792)	43,274
Interest expense, net	(13,092)	(12,285)	(26,043)	(24,747)
Other income (expense)				(19)
Total other income (expense), net	(29,669)	5,892	(46,835)	18,508
INCOME (LOSS) BEFORE INCOME TAXES	(19,036)	11,494	(21,660)	38,341
NET INCOME (LOSS)	$ (19,036)	$ 11,494	$ (21,660)	$ 38,341
NET INCOME (LOSS) PER COMMON SHARE
Basic	$ (0.06)	$ 0.04	$ (0.07)	$ 0.15
Diluted	$ (0.06)	$ 0.04	$ (0.07)	$ 0.15
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING
Basic	301,936	262,423	297,717	261,768
Diluted	301,936	264,420	297,717	264,321
Oil and Gas [Member]
REVENUES
Natural gas, oil and natural gas liquids sales	$ 103,257	$ 86,194	$ 213,441	$ 185,625
Natural Gas, Gathering, Transportation, Marketing and Processing [Member]
OPERATING EXPENSES
Transportation, gathering and compression	$ 31,371	$ 28,969	$ 59,060	$ 61,846