Condensed Consolidated Statements Of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Revenues:
Contract drilling	$ 133,420	$ 128,927	$ 421,198	$ 342,098
Oil and natural gas	131,420	134,897	397,745	376,393
Gas gathering and processing	52,935	60,688	159,977	144,820
Other	(15)	(667)	1,160	(566)
Total revenues	317,760	323,845	980,080	862,745
Contract drilling:
Operating costs	72,988	73,004	223,980	190,086
Depreciation	20,094	20,818	62,660	57,333
Oil and natural gas:
Operating costs	36,147	29,598	105,035	93,796
Depreciation, depletion and amortization	44,489	47,195	153,839	132,013
Impairment of oil and gas properties (Note 2)	0	0	115,874	0
Gas gathering and processing:
Operating costs	46,267	53,299	136,243	119,143
Depreciation and amortization	5,884	4,017	16,330	11,627
General and administrative	8,434	7,800	23,814	22,188
Interest, net	7,087	1,351	11,455	2,078
Total operating expenses	241,390	237,082	849,230	628,264
Income before income taxes	76,370	86,763	130,850	234,481
Income tax expense (benefit):
Current	2,516	(3,949)	450	(3,949)
Deferred	27,268	37,352	50,677	94,224
Total income taxes	29,784	33,403	51,127	90,275
Net income	$ 46,586	$ 53,360	$ 79,723	$ 144,206
Net income per common share:
Basic	$ 0.97	$ 1.12	$ 1.66	$ 3.03
Diluted	$ 0.97	$ 1.11	$ 1.66	$ 3.01