Business Segments - Assets (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 4,363,832		$ 4,221,901
Operating Segments | Contract Drilling
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	3,384,088		3,252,116
Operating Segments | Pressure Pumping
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	789,213		748,643
Operating Segments | Oil and Natural Gas
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	48,118		44,990
Corporate and other
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 142,413	[1]	$ 176,152	[1]

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