Derivative Financial Instruments (Impact Of Derivatives On Consolidated Statement Of Income) (Details) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Interest-Rate Contracts [Member] | Derivatives Designated As Fair Value Hedges [Member] | Processing Fees And Other Revenue [Member]
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	$ (171)	$ (48)	$ (161)	$ (138)
Interest-Rate Contracts [Member] | Derivatives Designated As Fair Value Hedges [Member] | Processing Fees And Other Revenue [Member] | Investment Securities Available For Sale [Member]
Amount of Gain (Loss) on Hedged Item Recognized in Consolidated Statement of Income	172	46	158	136
Interest-Rate Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Processing Fees And Other Revenue [Member]
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income		3		17
Interest-Rate Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Trading Services Revenue [Member]
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	43	(1)	(4)	(3)
Foreign Exchange Contracts [Member] | Derivatives Designated As Fair Value Hedges [Member] | Processing Fees And Other Revenue [Member]
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	(306)		(306)
Foreign Exchange Contracts [Member] | Derivatives Designated As Fair Value Hedges [Member] | Processing Fees And Other Revenue [Member] | Investment Securities [Member]
Amount of Gain (Loss) on Hedged Item Recognized in Consolidated Statement of Income	306		306
Foreign Exchange Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Processing Fees And Other Revenue [Member]
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	5	5	6	(2)
Foreign Exchange Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Trading Services Revenue [Member]
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	170	117	526	448
Long-Term Debt [Member] | Derivatives Designated As Fair Value Hedges [Member] | Processing Fees And Other Revenue [Member]
Amount of Gain (Loss) on Hedged Item Recognized in Consolidated Statement of Income	(42)	(26)	(56)	(61)
Derivatives Designated As Fair Value Hedges [Member]
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	(433)	(18)	(407)	(68)
Amount of Gain (Loss) on Hedged Item Recognized in Consolidated Statement of Income	436	20	408	75
Derivatives Designated As Fair Value Hedges [Member] | Processing Fees And Other Revenue [Member]
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	44	30	60	70
Derivatives Not Designated As Hedging Instruments [Member]
Amount of Gain (Loss) on Derivative Recognized in Consolidated Statement of Income	$ 218	$ 124	$ 528	$ 460