Property, Plant and Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment
Property, plant and equipment, gross	$ 14,436,262,000	$ 13,598,711,000
Less: accumulated depreciation and amortization	(5,724,174,000)	(4,928,781,000)
Less: accumulated depletion		(39,984,000)
Property, plant and equipment, net	8,712,088,000	8,629,946,000	7,815,419,000
Repair and maintenance expense	563,500,000	586,400,000	382,500,000
Interest costs capitalized	19,400,000	24,000,000	12,400,000
Land
Property, Plant and Equipment
Property, plant and equipment, gross	49,965,000	22,120,000
Buildings
Property, Plant and Equipment
Property, plant and equipment, gross	154,878,000	132,753,000
Dirlling, workover and well-servicing rigs, and related equipment
Property, Plant and Equipment
Property, plant and equipment, gross	12,364,021,000	11,150,927,000
Marine transportation and supply vessels
Property, Plant and Equipment
Property, plant and equipment, gross	14,054,000	14,023,000
Oilfield hauling and mobile equipment
Property, Plant and Equipment
Property, plant and equipment, gross	1,313,339,000	1,171,930,000
Other machinery and equipment
Property, Plant and Equipment
Property, plant and equipment, gross	176,468,000	248,938,000
Oil and gas properties
Property, Plant and Equipment
Property, plant and equipment, gross		42,033,000
Construction-in-progress
Property, Plant and Equipment
Property, plant and equipment, gross	$ 363,537,000	$ 815,987,000