Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Oil and gas sales	$ 65,034	$ 49,019	$ 169,134	$ 137,216
Costs and Expenses [Abstract]
General and administrative, net	5,486	6,031	16,856	22,676
Depreciation, depletion, and amortization	18,766	11,832	44,994	32,375
Accretion of asset retirement obligation	87	582	330	1,722
Lease operating costs	4,207	5,831	12,927	16,380
Transportation and gas processing	6,138	4,921	16,585	14,067
Severance and other taxes	2,464	2,479	8,156	6,377
Operating Expenses	37,148	31,676	99,848	93,597
Operating Income (Loss)	27,886	17,343	69,286	43,619
Net gain (loss) on commodity derivatives	(13,600)	(1,603)	(30,707)	14,465
Interest expense, net	(7,212)	(2,868)	(19,686)	(11,117)
Other Nonoperating Income (Expense)	226	12	(477)	(133)
Income (Loss) Before Income Taxes	7,300	12,884	18,416	46,834
Provision (Benefit) for Income Taxes	220	0	549	0
Net Income (Loss)	$ 7,080	$ 12,884	$ 17,867	$ 46,834
Per Share Amounts-
Earnings Per Share, Basic	$ 0.61	$ 1.12	$ 1.53	$ 4.10
Earnings Per Share, Diluted	$ 0.60	$ 1.12	$ 1.52	$ 4.08
Weighted Average Shares Outstanding - Basic	11,671	11,531	11,643	11,417
Weighted Average Shares Outstanding - Diluted	11,792	11,545	11,759	11,479