Industry Segment Information (Industry Segment Information) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Revenues:
Oil and natural gas	$ 188,207		$ 153,609
Contract drilling	124,258		119,353
Elimination of inter-segment revenue	(17,658)		(11,825)
Contract drilling net of inter-segment revenue	106,600		107,528
Gas gathering and processing	120,360		80,156
Elimination of inter-segment revenue	(27,179)		(22,761)
Gas gathering and processing net of inter-segment revenue	93,181		57,395
Total revenues	387,988		318,532
Operating income
Oil and natural gas	(88,112)		(58,588)
Contract drilling	(24,401)		24,266
Gas gathering and processing	(2,630)		829
Total operating income	115,143	[1]	83,683	[1]
General and administrative expense	(9,637)		(8,673)
Gain (loss) on disposition of assets	9,426		(84)
Loss on derivatives not designated as hedges and hedge ineffectiveness, net	(18,366)		(5,924)
Interest expense, net	(3,790)		(3,561)
Other	120		(66)
Income before income taxes	$ 92,896		$ 65,375

[1] Operating income 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 and hedge ineffectiveness, interest expense, other income (loss), or income taxes.