Derivative Financial Instruments (Impact Of Derivatives On Consolidated Statement Of Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	$ 128	$ 156	$ 257	$ 310
Derivatives Designated As Fair Value Hedges [Member]
Derivative [Line Items]
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	(1)	3	38	26
Amount of Gain (Loss) on Hedged Item Recognized in Consolidated Statement of Income	5	(6)	(39)	(28)
Derivatives Designated As Fair Value Hedges [Member] | Processing Fees And Other Revenue [Member] | Long-Term Debt [Member]
Derivative [Line Items]
Amount of Gain (Loss) on Hedged Item Recognized in Consolidated Statement of Income				(14)
Derivatives Designated As Fair Value Hedges [Member] | Processing Fees And Other Revenue [Member] | Investment Securities Available For Sale [Member]
Derivative [Line Items]
Amount of Gain (Loss) on Hedged Item Recognized in Consolidated Statement of Income				(14)
Interest Rate Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Processing Fees And Other Revenue [Member]
Derivative [Line Items]
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income		0	2	0
Interest Rate Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Trading Services Revenue [Member]
Derivative [Line Items]
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income		(8)	(88)	(18)
Interest Rate Contracts [Member] | Derivatives Designated As Fair Value Hedges [Member] | Processing Fees And Other Revenue [Member] | Long-Term Debt [Member]
Derivative [Line Items]
Amount of Gain (Loss) on Hedged Item Recognized in Consolidated Statement of Income	(50)	(17)	(37)
Interest Rate Contracts [Member] | Derivatives Designated As Fair Value Hedges [Member] | Processing Fees And Other Revenue [Member] | Investment Securities Available For Sale [Member]
Derivative [Line Items]
Amount of Gain (Loss) on Hedged Item Recognized in Consolidated Statement of Income	29	11	2
Interest Rate Contracts [Member] | Derivatives Designated As Fair Value Hedges [Member] | Processing Fees And Other Revenue [Member] | Contract One [Member]
Derivative [Line Items]
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	56	19	40	16
Interest Rate Contracts [Member] | Derivatives Designated As Fair Value Hedges [Member] | Processing Fees And Other Revenue [Member] | Contract Two [Member]
Derivative [Line Items]
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	(31)	(16)	(6)	10
Foreign Exchange Contracts [Member]
Derivative [Line Items]
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income			0
Foreign Exchange Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Processing Fees And Other Revenue [Member]
Derivative [Line Items]
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	(1)	(4)	(3)	1
Foreign Exchange Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Trading Services Revenue [Member]
Derivative [Line Items]
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	129	168	346	327
Foreign Exchange Contracts [Member] | Derivatives Designated As Fair Value Hedges [Member] | Processing Fees And Other Revenue [Member] | Investment Securities [Member]
Derivative [Line Items]
Amount of Gain (Loss) on Hedged Item Recognized in Consolidated Statement of Income	26		(4)
Foreign Exchange Contracts [Member] | Derivatives Designated As Fair Value Hedges [Member] | Processing Fees And Other Revenue [Member] | Contract Three [Member]
Derivative [Line Items]
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	$ (26)		$ 4