Condensed Consolidated Statements Of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Revenues:
Oil and natural gas	$ 153,609	$ 135,765
Contract drilling	107,528	140,906
Gas gathering and processing	57,395	57,295
Total revenues	318,532	333,966
Oil and natural gas:
Operating costs	43,038	35,609
Depreciation, depletion, and amortization	51,983	52,197
Contract drilling:
Operating costs	66,002	76,173
Depreciation	17,260	21,328
Gas gathering and processing:
Operating costs	49,410	47,613
Depreciation and amortization	7,156	5,134
General and administrative	8,673	7,004
Total operating expenses	243,522	245,058
Income from operations	75,010	88,908
Other income (expense):
Interest, net	(3,561)	(1,826)
Loss on derivatives not designated as hedges and hedge ineffectiveness, net	(5,924)	(1,993)
Other	(150)	455
Total other expense	(9,635)	(3,364)
Income before income taxes	65,375	85,544
Income tax expense:
Current	2,517	0
Deferred	22,652	33,105
Total income taxes	25,169	33,105
Net income	$ 40,206	$ 52,439
Net income per common share:
Basic	$ 0.84	$ 1.10
Diluted	$ 0.83	$ 1.09