Industry Segment Information (Industry Segment Information) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues:
Oil and natural gas		$ 96,619	$ 188,471	$ 309,944	$ 575,176
Contract drilling		68,426	147,866	234,177	407,905
Elimination of inter-segment revenue		(3,404)	(27,214)	(19,063)	(66,375)
Contract drilling net of inter-segment revenue		65,022	120,652	215,114	341,530
Gas gathering and processing		66,836	113,467	209,803	350,181
Elimination of inter-segment revenue		(16,084)	(21,616)	(52,922)	(72,494)
Gas gathering and processing net of inter-segment revenue		50,752	91,851	156,881	277,687
Total revenues		212,393	400,974	681,939	1,194,393
Operating income (loss):
Oil and natural gas		(329,152)	69,597	(1,163,358)	240,239
Contract drilling		15,281	31,365	40,550	83,311
Gas gathering and processing		(538)	3,021	(718)	9,549
Total operating income (loss)	[1]	(314,409)	103,983	(1,123,526)	333,099
General and administrative		(7,643)	(10,172)	(26,637)	(30,409)
Gain (loss) on disposition of assets		(7,230)	(529)	(6,270)	9,092
Gain (loss) on derivatives not designated as hedges		8,250	19,841	12,917	(9,234)
Interest expense, net		(8,286)	(4,280)	(23,482)	(12,201)
Other		16	(68)	38	3
Income (loss) before income taxes		$ (329,302)	$ 108,775	$ (1,166,960)	$ 290,350

[1] Operating income (loss) is total operating revenues less operating expenses, depreciation, depletion, amortization, and impairment and does not include general corporate expenses, gain (loss) on disposition of assets, gain (loss) on non-designated hedges, interest expense, other income (loss), or income taxes.