Fair Value (Fair Value Option - Summary Of Changes Included In The Condensed Consolidated Statement Of Income) (Details) (Mortgage Loans Held-For-Sale [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	$ (25)	$ (33)
Interest on loans held-for-sale [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	16	26
Gain on mortgage loans, net [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	$ (41)	$ (59)