Long-Lived Asset Impairments Narrative (Details) - USD ($) $ in Millions	3 Months Ended				12 Months Ended
	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Impaired Long-Lived Assets Held and Used [Line Items]
Long-Lived Asset Impairments			$ 352		$ 638	$ 495	$ 0
Long-Lived Asset Impairments and Other Related Charges					768	$ 495	$ 0
Drilling Rigs [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Long-Lived Asset Impairments					$ 255
Land Drilling and Workover Rig Operations [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Long-Lived Asset Impairments and Other Related Charges				$ 143
Pressure Pumping [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Long-Lived Asset Impairments	$ 72	$ 124
Drilling Tools [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Long-Lived Asset Impairments	126
Wireline [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Long-Lived Asset Impairments	$ 61