Fair Value Disclosures (Fair Value Measured on Nonrecurring Basis) (Details) (Fair Value, Measurements, Nonrecurring [Member], Level 3 [Member], USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans (excluding covered)	$ 187	$ 50
Valuation adjustments to impaired loans (excluding covered)	(47)	(41)
Foreclosed real estate (excluding covered)	75	71
Valuation adjustments on foreclosed real estate (excluding covered)	$ 3	$ (6)