Business Segments - Revenues (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Segment Reporting, Revenue Reconciling Item [Line Items]
Oil and natural gas	$ 14,717		$ 14,690		$ 31,502		$ 29,407
Total operating revenues	659,316		681,112		1,326,355		1,427,033
Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Oil and natural gas	14,717		14,690		31,502		29,407
Total operating revenues	660,549		682,661		1,328,727		1,429,803
Operating Segments | Contract Drilling
Segment Reporting, Revenue Reconciling Item [Line Items]
Oil and gas services	391,212		461,798		811,445		952,501
Operating Segments | Pressure Pumping
Segment Reporting, Revenue Reconciling Item [Line Items]
Oil and gas services	254,620		206,173		485,780		447,895
Intercompany Elimination
Segment Reporting, Revenue Reconciling Item [Line Items]
Total operating revenues	$ (1,233)	[1]	$ (1,549)	[1]	$ (2,372)	[1]	$ (2,770)	[1]

[1] Consists of contract drilling intercompany revenues for drilling services provided to the oil and natural gas exploration and production segment.