Derivative and Hedging Activities - Derivative Instruments, Gain/Loss In Statement Of Financial Performance Table (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate contracts	$ (58)	$ 7	$ (14)
Fair Value Hedging | Interest rate contract | Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate contracts	$ 5	$ 8	$ 16