Derivative Instruments and Hedging Activities (Details 1) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Commodity Contract [Member]
Effect of derivative instruments designated as fair value hedges and not designated as hedges on the consolidated statement of income
Commodity forward contract outstanding	$ 27
Fair Value Hedging [Member]
Effect of derivative instruments designated as fair value hedges and not designated as hedges on the consolidated statement of income
Gain/(loss) recognized in income	9	14	111
Fair Value Hedging [Member] | Foreign Exchange Contract [Member] | Cost of revenue - Oilfield Services [Member]
Effect of derivative instruments designated as fair value hedges and not designated as hedges on the consolidated statement of income
Gain/(loss) recognized in income		(8)	105
Fair Value Hedging [Member] | Interest Rate Contract [Member] | Interest expense [Member]
Effect of derivative instruments designated as fair value hedges and not designated as hedges on the consolidated statement of income
Gain/(loss) recognized in income	9	22	6
Nondesignated [Member]
Effect of derivative instruments designated as fair value hedges and not designated as hedges on the consolidated statement of income
Gain/(loss) recognized in income	(22)	(12)	34
Nondesignated [Member] | Foreign Exchange Contract [Member] | Cost of revenue - Oilfield Services [Member]
Effect of derivative instruments designated as fair value hedges and not designated as hedges on the consolidated statement of income
Gain/(loss) recognized in income	(17)	(13)	32
Nondesignated [Member] | Commodity Contract [Member] | Cost of revenue - Oilfield Services [Member]
Effect of derivative instruments designated as fair value hedges and not designated as hedges on the consolidated statement of income
Gain/(loss) recognized in income	$ (5)	$ 1	$ 2