Fair Value Election and Measurement Level 3 Significant Unobservable Input Assumptions (parenthetical) (Details) (Visa Interest [Member], Derivative Financial Instruments, Liabilities [Member], Not Designated as Hedging Instrument [Member], USD $) In Millions, unless otherwise specified	Jun. 30, 2013
Visa Interest [Member] | Derivative Financial Instruments, Liabilities [Member] | Not Designated as Hedging Instrument [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Other Liabilities, Fair Value Disclosure	$ 2