Derivatives (Details 3-IS & OCI) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Net interest and other [Member] | Interest rate [Member]
Gain (Loss) on Derivative Instruments [Line Items]
Gain (loss) on derivative instruments recognized in income	$ (12)	$ 12	$ (15)	$ 12
Net interest and other [Member] | Long-term Debt [Member]
Gain (Loss) on Derivative Instruments [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	12	(12)	15	(12)
Provision For Income Taxes [Member] | Foreign Exchange Contract [Member]
Gain (Loss) on Derivative Instruments [Line Items]
Gain (loss) on derivative instruments recognized in income	(21)	(32)	(46)	(40)
Provision For Income Taxes [Member] | Accrued Taxes [Member]
Gain (Loss) on Derivative Instruments [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	$ 21	$ 32	$ 46	$ 40