Business Segments - Revenues (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Segment Reporting Revenue Reconciling Item [Line Items]
Oil and natural gas	$ 14,724		$ 13,827		$ 38,844		$ 45,329
Total revenues	845,628		730,907		2,281,072		2,057,262
Contract Drilling
Segment Reporting Revenue Reconciling Item [Line Items]
Oil and gas services	482,212		457,871		1,346,698		1,266,944
Pressure Pumping
Segment Reporting Revenue Reconciling Item [Line Items]
Oil and gas services	348,692		259,209		895,530		744,989
Operating Segments
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenues	848,027		732,249		2,285,974		2,060,976
Operating Segments | Contract Drilling
Segment Reporting Revenue Reconciling Item [Line Items]
Oil and gas services	483,307		459,213		1,350,296		1,270,658
Operating Segments | Pressure Pumping
Segment Reporting Revenue Reconciling Item [Line Items]
Oil and gas services	349,996		259,209		896,834		744,989
Intersegment Elimination
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenues	$ (2,399)	[1]	$ (1,342)	[1]	$ (4,902)	[1]	$ (3,714)	[1]

[1] Consists of contract drilling and, in 2014, pressure pumping intercompany revenues for services provided to the oil and natural gas exploration and production segment.