Goodwill (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2014	Dec. 31, 2012
Goodwill [Line Items]
Goodwill impairment loss	$ 40	$ (125)	$ 66	$ 589
Latin America [Member]
Goodwill [Line Items]
Goodwill impairment loss	15		15
Europe/Sub-Sahara Africa/Russia [Member]
Goodwill [Line Items]
Goodwill impairment loss	13	77	39
Middle East/North Africa/Asia [Member]
Goodwill [Line Items]
Goodwill impairment loss	12	512	12
Land Drilling and Workover Rig Operations [Member]
Goodwill [Line Items]
Goodwill impairment loss		121
Goodwill impairment (classified as assets held for sale)		$ 95