Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues
Oil and natural gas	$ 357,744	$ 294,221	$ 385,774
Contract drilling	174,720	122,086	265,668
Gas gathering and processing	207,176	185,870	202,789
Total revenues	739,640	602,177	854,231
Operating costs:
Oil and natural gas	130,789	120,184	166,046
Contract drilling	122,600	88,154	156,408
Gas gathering and processing	155,483	137,609	161,556
Total operating costs	408,872	345,947	484,010
Depreciation, depletion, and amortization	209,257	208,353	352,742
Impairments	0	161,563	1,634,628
General and administrative	38,087	33,337	34,358
(Gain) loss on disposition of assets	(327)	(2,540)	7,229
Total expenses	655,889	746,660	2,512,967
Income (loss) from operations	83,751	(144,483)	(1,658,736)
Other income (expense):
Interest, net	(38,334)	(39,829)	(31,963)
Gain (loss) on derivatives	14,732	(22,813)	26,345
Other	21	307	45
Total other income (expense)	(23,581)	(62,335)	(5,573)
Income (loss) before income taxes	60,170	(206,818)	(1,664,309)
Income tax expense (benefit):
Current	5	15	(20,616)
Deferred	(57,683)	(71,209)	(606,332)
Total income taxes	(57,678)	(71,194)	(626,948)
Net income (loss)	$ 117,848	$ (135,624)	$ (1,037,361)
Net income (loss) per common share:
Basic	$ 2.31	$ (2.71)	$ (21.12)
Diluted	$ 2.28	$ (2.71)	$ (21.12)