Goodwill (Schedule of Goodwill) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($)
Goodwill [Line Items]
Goodwill, Purchase Accounting Adjustments	$ 1
Goodwill, Acquired During Period	2
Goodwill [Roll Forward]
Balance at December 31, 2014	3,011
Foreign currency translation adjustments	(170)
Balance at September 30, 2015	2,844
North America [Member]
Goodwill [Line Items]
Goodwill, Purchase Accounting Adjustments	0
Goodwill, Acquired During Period	2
Goodwill [Roll Forward]
Balance at December 31, 2014	1,896
Foreign currency translation adjustments	(118)
Balance at September 30, 2015	1,780
MENA/ Asia Pacific [Member]
Goodwill [Line Items]
Goodwill, Purchase Accounting Adjustments	1
Goodwill, Acquired During Period	0
Goodwill [Roll Forward]
Balance at December 31, 2014	195
Foreign currency translation adjustments	(8)
Balance at September 30, 2015	188
Europe/ SSA/ Russia [Member]
Goodwill [Line Items]
Goodwill, Purchase Accounting Adjustments	0
Goodwill, Acquired During Period	0
Goodwill [Roll Forward]
Balance at December 31, 2014	623
Foreign currency translation adjustments	(33)
Balance at September 30, 2015	590
Latin America [Member]
Goodwill [Line Items]
Goodwill, Purchase Accounting Adjustments	0
Goodwill, Acquired During Period	0
Goodwill [Roll Forward]
Balance at December 31, 2014	297
Foreign currency translation adjustments	(11)
Balance at September 30, 2015	286
Land Drilling Rigs [Member]
Goodwill [Line Items]
Goodwill, Purchase Accounting Adjustments	0
Goodwill, Acquired During Period	0
Goodwill [Roll Forward]
Balance at December 31, 2014	0
Foreign currency translation adjustments	$ 0