Property, Plant and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment
Property, plant and equipment, gross	$ 13,556,735	$ 13,336,457
Less: accumulated depreciation and amortization	(7,289,152)	(6,308,655)
Property, Plant and Equipment, Net, Total	6,267,583	7,027,802	$ 8,599,125
Depreciation	855,400	951,400	1,100
Repair and maintenance expense	151,400	304,700	603,400
Interest costs capitalized	6,700	20,400	$ 24,400
Land
Property, Plant and Equipment
Property, plant and equipment, gross	46,319	19,757
Buildings
Property, Plant and Equipment
Property, plant and equipment, gross	115,502	126,285
Drilling, Workover and Well Servicing Rigs and Related Equipment [Member]
Property, Plant and Equipment
Property, plant and equipment, gross	12,638,749	12,243,811
Marine Transportation and Supply Vessels
Property, Plant and Equipment
Property, plant and equipment, gross		10,271
Oilfield Hauling and Mobile Equipment
Property, Plant and Equipment
Property, plant and equipment, gross	274,137	286,838
Other Machinery and Equipment
Property, Plant and Equipment
Property, plant and equipment, gross	181,069	175,687
Construction in Progress
Property, Plant and Equipment
Property, plant and equipment, gross	288,673	457,422
Oil and Gas Properties
Property, Plant and Equipment
Property, plant and equipment, gross	$ 12,286	$ 16,386