Fair Value Disclosures (Fair Value Measured on Nonrecurring Basis) (Details) (Fair Value, Measurements, Nonrecurring [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans (excluding covered)	$ 50	$ 137
Valuation adjustments to impaired loans (excluding covered)	(41)	(109)
Foreclosed real estate (excluding covered)	71	107
Valuation adjustments on foreclosed real estate (excluding covered)	$ (6)	$ (147)