Summary of Significant Accounting Policies (Details 3) (USD $)	12 Months Ended		3 Months Ended		12 Months Ended					12 Months Ended					12 Months Ended		12 Months Ended				12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Jun. 30, 2012 Peak USA	Dec. 31, 2012 Peak USA	Dec. 31, 2012 Drilling and Rig Services	Dec. 31, 2011 Drilling and Rig Services	Dec. 31, 2012 U.S. Lower 48 Land Drilling	Dec. 31, 2011 U.S. Lower 48 Land Drilling	Dec. 31, 2010 U.S. Lower 48 Land Drilling	Dec. 31, 2012 U.S. Offshore	Dec. 31, 2010 U.S. Offshore	Dec. 31, 2012 Alaska	Dec. 31, 2011 Alaska	Dec. 31, 2010 Alaska	Dec. 31, 2012 International	Dec. 31, 2010 International	Dec. 31, 2012 Other Rig Services	Dec. 31, 2011 Other Rig Services	Dec. 31, 2011 Completion and Production Services	Dec. 31, 2012 Completion and Production Services	Dec. 31, 2011 U.S. Land Well-servicing
Change in the carrying amount of goodwill for various contract drilling segments and other operating segments
Beginning Balance	$ 501,258,000	$ 494,372,000			$ 111,194,000	$ 103,541,000	$ 30,154,000	$ 30,154,000	$ 30,154,000	$ 7,296,000	$ 7,296,000	$ 19,995,000	$ 19,995,000	$ 19,995,000	$ 18,983,000	$ 18,983,000	$ 34,766,000	$ 27,113,000	$ 390,831,000	$ 390,064,000
Acquisitions and purchase price adjustment		7,233,000				8,000,000												8,000,000	(767,000)		(767,000)
Disposals and Impairments	(29,314,000)				(29,314,000)					(7,296,000)					(18,983,000)		(3,035,000)
Cumulative Translation Adjustment	382,000	(347,000)			382,000	(347,000)											382,000	(347,000)
Ending Balance	472,326,000	501,258,000			82,262,000	111,194,000	30,154,000	30,154,000	30,154,000		7,296,000	19,995,000	19,995,000	19,995,000		18,983,000	32,113,000	34,766,000	390,064,000	390,064,000
Discontinued Operation, additional disclosures
Equity interest (as a percent)				50.00%
Value of sale of Peak USA to an unrelated third party	159,529,000	142,984,000	13,500,000
Goodwill for the consolidated company, expected to be deductible for tax purposes	$ 11,500,000