Segment Information (Schedule of Segment Reporting Information) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Segment Reporting Information [Line Items]
Identifiable assets	$ 1,303,184	$ 946,888	$ 1,303,184	$ 946,888	$ 1,172,754
Drilling services, revenues	125,662	108,764	369,014	315,043
Production services, revenues	104,111	78,887	322,561	197,242
Total revenues	229,773	187,651	691,575	512,285
Drilling services, operating costs	88,188	72,430	247,896	213,129
Production services, operating costs	65,395	44,394	191,774	115,376
Operating costs	153,583	116,824	439,670	328,505
Segment margin	76,190	70,827	251,905	183,780
Depreciation and amortization	42,067	32,992	120,429	97,672
Capital expenditures	83,405	59,838	304,758	158,338
Drilling Services Division [Member]
Segment Reporting Information [Line Items]
Identifiable assets	837,887	645,104	837,887	645,104
Segment margin	37,474	36,334	121,118	101,914
Depreciation and amortization	27,467	24,405	79,263	73,594
Capital expenditures	56,734	44,597	217,926	110,352
Production Services Division [Member]
Segment Reporting Information [Line Items]
Identifiable assets	441,791	269,080	441,791	269,080
Segment margin	38,716	34,493	130,787	81,866
Depreciation and amortization	14,399	8,388	40,508	23,393
Capital expenditures	26,269	15,241	85,457	47,986
Corporate [Member]
Segment Reporting Information [Line Items]
Identifiable assets	23,506	32,704	23,506	32,704
Segment margin	0	0	0	0
Depreciation and amortization	201	199	658	685
Capital expenditures	$ 402	$ 0	$ 1,375	$ 0