Fair Value (Level 3 Total Realized And Unrealized Gains And Losses Recorded In Revenue) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Trading Services [Member]
Realized and Unrealized Gains and Losses [Line Items]
Total Realized and Unrealized Gains (Losses) Recorded in Revenue	$ (13)	$ 17	$ 38
Change in Unrealized Gains (Losses) Related to Financial Instruments Held	(9)	(5)	(5)
Total Fee Revenue [Member]
Realized and Unrealized Gains and Losses [Line Items]
Total Realized and Unrealized Gains (Losses) Recorded in Revenue	(13)	17	88
Change in Unrealized Gains (Losses) Related to Financial Instruments Held	(9)	(5)	45
Processing Fees And Other Revenue [Member]
Realized and Unrealized Gains and Losses [Line Items]
Total Realized and Unrealized Gains (Losses) Recorded in Revenue			50
Change in Unrealized Gains (Losses) Related to Financial Instruments Held			50
Net Interest Revenue [Member]
Realized and Unrealized Gains and Losses [Line Items]
Total Realized and Unrealized Gains (Losses) Recorded in Revenue	561	141	(101)
Total Revenue [Member]
Realized and Unrealized Gains and Losses [Line Items]
Total Realized and Unrealized Gains (Losses) Recorded in Revenue	548	158	(13)
Change in Unrealized Gains (Losses) Related to Financial Instruments Held	$ (9)	$ (5)	$ 45