Business Segments - Assets (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 4,663,716		$ 4,556,911
Operating Segments | Contract Drilling
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	3,589,704		3,538,289
Operating Segments | Pressure Pumping
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	838,832		784,128
Operating Segments | Oil and Natural Gas
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	53,373		54,188
Corporate and other
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 181,807	[1]	$ 180,306	[1]

[1] Corporate and other assets primarily include cash on hand and certain deferred tax assets.