Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenues:
Drilling services									$ 433,902	$ 312,196	$ 219,751
Production services									282,039	175,014	105,786
Total revenues	203,656	187,651	171,285	153,349	148,618	135,544	117,027	86,021	715,941	487,210	325,537
Costs and expenses:
Drilling services									292,559	227,136	147,343
Production services									164,365	105,295	68,012
Depreciation and amortization									132,832	120,811	106,186
General and administrative									67,318	52,047	37,478
Bad debt expense (recovery)									925	493	(1,642)
Impairment of equipment									484	0	0
Total costs and expenses									658,483	505,782	357,377
Income (loss) from operations	20,297	19,324	11,918	5,919	6,864	2,536	(7,856)	(20,116)	57,458	(18,572)	(31,840)
Other (expense) income:
Interest expense									(29,721)	(26,567)	(8,928)
Impairment of investments									0	(3,331)	0
Other									(6,904)	912	596
Total other expense									(36,625)	(28,986)	(8,332)
Income (loss) before income taxes									20,833	(47,558)	(40,172)
Income tax (expense) benefit	(5,469)	(5,250)	(1,039)	2,102	(972)	1,612	4,498	9,159	(9,656)	14,297	16,957
Net income (loss)	$ 6,818	$ 6,744	$ 3,650	$ (6,035)	$ (5,992)	$ (2,580)	$ (10,142)	$ (14,547)	$ 11,177	$ (33,261)	$ (23,215)
Income (loss) per common share - Basic	$ 0.11	$ 0.11	$ 0.07	$ (0.11)	$ (0.11)	$ (0.05)	$ (0.19)	$ (0.27)	$ 0.19	$ (0.62)	$ (0.46)
Income (loss) per common share - Diluted	$ 0.11	$ 0.11	$ 0.07	$ (0.11)	$ (0.11)	$ (0.05)	$ (0.19)	$ (0.27)	$ 0.19	$ (0.62)	$ (0.46)
Weighted average number of shares outstanding - Basic									57,390	53,797	50,313
Weighted-average number of shares outstanding - Diluted									58,779	53,797	50,313