Goodwill Schedule of Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Goodwill [Roll Forward]
Beginning Balance	$ 3,011	$ 3,290
Goodwill Acquired	3	6
Impairment loss		(66)
Purchase price and other adjustments	1	(5)
Foreign currency translation adjustments	(212)	(214)
Ending Balance	2,803	3,011
North America [Member]
Goodwill [Roll Forward]
Beginning Balance	1,896	1,981
Goodwill Acquired	3	0
Purchase price and other adjustments	0	1
Foreign currency translation adjustments	(143)	(86)
Ending Balance	1,756	1,896
Middle East/North Africa/Asia [Member]
Goodwill [Roll Forward]
Beginning Balance	195	196
Goodwill Acquired	0	6
Purchase price and other adjustments	1	0
Foreign currency translation adjustments	(6)	(7)
Ending Balance	190	195
Europe/Sub-Sahara Africa/Russia [Member]
Goodwill [Roll Forward]
Beginning Balance	623	753
Goodwill Acquired	0	0
Impairment loss		(26)
Purchase price and other adjustments	0	8
Foreign currency translation adjustments	(50)	(112)
Ending Balance	573	623
Latin America [Member]
Goodwill [Roll Forward]
Beginning Balance	297	304
Goodwill Acquired	0	0
Purchase price and other adjustments	0	0
Foreign currency translation adjustments	(13)	(7)
Ending Balance	284	297
Drilling Rigs [Member]
Goodwill [Roll Forward]
Beginning Balance	0	56
Goodwill Acquired	0	0
Impairment loss		(40)
Purchase price and other adjustments	0	(14)
Foreign currency translation adjustments	0	(2)
Ending Balance	$ 0	$ 0