Industry Segment Information (Revenue From Different Segments) (Details) (USD $) In Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010
Industry Segment Information
Contract drilling	$ 140,193		$ 96,705		$ 381,982		$ 246,252
Elimination of inter-segment revenue	(11,266)		(11,701)		(39,884)		(28,333)
Contract drilling net of inter-segment revenue	128,927		85,004		342,098		217,919
Oil and natural gas	134,897		96,562		376,393		286,751
Gas gathering and processing	79,919		47,864		200,821		148,606
Elimination of inter-segment revenue	(19,231)		(10,435)		(56,001)		(33,698)
Gas gathering and processing net of inter-segment revenue	60,688		37,429		144,820		114,908
Other, net	(667)		(879)		(566)		9,691
Total revenues	323,845		218,116		862,745		629,269
Contract drilling	35,105		21,129		94,679		36,372
Oil and natural gas	58,104		39,379		150,584		129,062
Gas gathering and processing	3,372		2,863		14,050		10,755
Total operating income	96,581	[1]	63,371	[1]	259,313	[1]	176,189	[1]
General and administrative expense	(7,800)		(6,637)		(22,188)		(19,372)
Interest expense, net	(1,351)		0		(2,078)		0
Other income (loss), net	(667)		(879)		(566)		9,691
Income before income taxes	$ 86,763		$ 55,855		$ 234,481		$ 166,508

[1] Operating income is total operating revenues less operating expenses, depreciation, depletion and amortization and does not include non-operating revenues, general corporate expenses, interest expense or income taxes.