Derivatives (Details 3-Fair Value Hedges IS & OCI) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net interest and other [Member]
Gain (Loss) on Derivative Instruments [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	$ (5)	$ (6)	$ 9	$ (17)
Provision For Income Taxes [Member]
Gain (Loss) on Derivative Instruments [Line Items]
Change in unrealized gain (loss) on hedged item in fair value hedge	(5)	(22)	41	18
Interest rate [Member] | Net interest and other [Member]
Gain (Loss) on Derivative Instruments [Line Items]
Gain (loss) on derivative instruments recognized in income	5	6	(9)	17
Foreign Exchange Contract [Member] | Provision For Income Taxes [Member]
Gain (Loss) on Derivative Instruments [Line Items]
Gain (loss) on derivative instruments recognized in income	$ 5	$ 22	$ (41)	$ (18)