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		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 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	44	(80)	73	(88)
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	$ (44)	$ 80	$ (73)	$ 88