Derivative Financial Instruments and Hedging Activities Amounts Recognized in Net Income (Details) (Interest expense - net [Member], Fair Value Hedging [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in net income	$ 0	$ 0	$ 0	$ 0
Fixed-to-floating interest rate swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in net income	(12)	5	61	(83)
Related Long Term Debt Converted To Floating Interest Rates By Interest Rate Swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in net income	$ 12	$ (5)	$ (61)	$ 83