Nature of Operations (Details)	3 Months Ended
	Mar. 31, 2013 item rig
Nature of Operations
Number of major business lines	2
Number of platform rigs actively marketed	37
Number of jack-up rigs actively marketed	7
Number of barge rigs actively marketed	4
Number of hydraulic horsepower pressure pumping services in key basins throughout United States and Canada	800,000
Nature of operations
Number of actively marketed land drilling rigs	473
Number of states in which oil, gas and geothermal land drilling operations are conducted	48
Minimum number of countries in which oil and gas land drilling operations are conducted	20
Joint Venture in Saudi Arabia
Nature of Operations
Ownership percentage	51.00%
Number of rigs actively markets in joint venture	5
U.S.
Nature of Operations
Number of rigs marketing for land well-servicing and workover service	442
Canada
Nature of Operations
Number of rigs marketing for land well-servicing and workover service	104