Servicing Activities (Components Of Servicing Valuation And Hedge Activities) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Components of Servicing Valuation and Hedge Activities [Line Items]
Net realized/unrealized gains (losses) included in earnings, Assets	$ (131)	$ 60
Servicing asset valuation and hedge activities, net	(201)	(106)
Not Designated as Hedging Instrument [Member] | Interest Rate Contract [Member]
Components of Servicing Valuation and Hedge Activities [Line Items]
Servicing asset valuation and hedge activities, net	(112)	(96)
Mortgage Servicing Rights [Member]
Components of Servicing Valuation and Hedge Activities [Line Items]
Net realized/unrealized gains (losses) included in earnings, Assets	$ (89)	$ (10)