Shareholders' Equity (Adjustments to Accumulated Other Comprehensive Income) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Class of Stock [Line Items]
Net interest revenue	$ 2,303	$ 2,538	$ 2,333
Net gains (losses) from sales of available-for-sale securities	14
Processing fees and other revenue	95	134	(216)
Total reclassifications out of AOCI	2,102	2,019	1,882
Reclassification out of Accumulated Other Comprehensive Income [Member]
Class of Stock [Line Items]
Total reclassifications out of AOCI	20
Net Unrealized Gains (Losses) on Cash Flow Hedges | Interest-rate contracts | Reclassification out of Accumulated Other Comprehensive Income [Member]
Class of Stock [Line Items]
Net interest revenue	3
Interest-rate contract, tax	2
Net Unrealized Gains (Losses) on Available-for-Sale Securities | Reclassification out of Accumulated Other Comprehensive Income [Member]
Class of Stock [Line Items]
Net gains (losses) from sales of available-for-sale securities	9
Net realized gain from sales of available-for-sale securities, tax	(5)
Other-Than-Temporary Impairment on Held-to-Maturity Securities | Reclassification out of Accumulated Other Comprehensive Income [Member]
Class of Stock [Line Items]
Available-for-sale securities, Losses reclassified (from) to other comprehensive income	4
Held-to-maturity securities, Losses reclassified (from) to other comprehensive income	3
Other-than-temporary impairment on available-for-sale securities related to factors other than credit, tax	2
Other-than-temporary impairment on held-to-maturity securities related to factors other than credit, tax	3
Net Unrealized Losses on Retirement Plans | Reclassification out of Accumulated Other Comprehensive Income [Member]
Class of Stock [Line Items]
Amortization of actuarial losses, net of related tax benefit of $13	20
Amortization of actuarial losses, tax	13
Foreign Currency Translation | Reclassification out of Accumulated Other Comprehensive Income [Member]
Class of Stock [Line Items]
Processing fees and other revenue	(1)
Sale of foreign entities, tax	$ (1)