Fair Value (Level 3 Total Realized And Unrealized Gains And Losses Recorded In Revenue) (Details) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Trading Services [Member]
Total Realized and Unrealized Gains (Losses) Recorded in Revenue	$ 12	$ (4)	$ 1	$ 36
Change in Unrealized Gains (Losses) Related to Financial Instruments Held		9	7	18
Total Fee Revenue [Member]
Total Realized and Unrealized Gains (Losses) Recorded in Revenue	12	(4)	1	36
Change in Unrealized Gains (Losses) Related to Financial Instruments Held		9	7	18
Net Interest Revenue [Member]
Total Realized and Unrealized Gains (Losses) Recorded in Revenue	37	30	391	(45)
Total Revenue [Member]
Total Realized and Unrealized Gains (Losses) Recorded in Revenue	49	26	392	(9)
Change in Unrealized Gains (Losses) Related to Financial Instruments Held		$ 9	$ 7	$ 18