Derivative Instruments And Hedging Activities (Fair Value Amounts Of Derivative Instruments Reported On Our Condensed Consolidated Balance Sheet) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 668	$ 2,298
Derivative Liability, Fair Value, Gross Liability	406	2,468
Notional amount	97,835	236,237
Accrued Interest [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	127	175
Derivative Liability, Fair Value, Gross Liability	16	144
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	300	446
Derivative Liability, Fair Value, Gross Liability	22	63
Notional amount	18,521	18,521
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	368	1,852
Derivative Liability, Fair Value, Gross Liability	384	2,405
Notional amount	79,314	217,716
Interest Rate Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	279	411
Derivative Liability, Fair Value, Gross Liability	1	10
Notional amount	8,784	9,828
Interest Rate Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	337	1,847
Derivative Liability, Fair Value, Gross Liability	382	2,378
Notional amount	76,685	215,252
Fair Value Hedging [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	279	411
Derivative Liability, Fair Value, Gross Liability	0	0
Notional amount	6,910	7,248
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	1	10
Notional amount	1,874	2,580
Mortgage Servicing Rights And Retained Interests [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	158	1,616
Derivative Liability, Fair Value, Gross Liability	329	2,299
Notional amount	7,401	146,405
Mortgage Loan Commitments And Mortgage Loans Held-For-Sale [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	10	49
Derivative Liability, Fair Value, Gross Liability	5	23
Notional amount	2,238	9,617
Debt Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	28	28
Derivative Liability, Fair Value, Gross Liability	20	29
Notional amount	12,150	17,716
Other [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	141	154
Derivative Liability, Fair Value, Gross Liability	28	27
Notional amount	54,896	41,514
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	31	5
Derivative Liability, Fair Value, Gross Liability	2	27
Notional amount	2,629	2,464
Net Investment Hedging [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	21	35
Derivative Liability, Fair Value, Gross Liability	21	53
Notional amount	$ 9,737	$ 8,693