Fair Value (Fair Value Option - Changes in Fair Value) (Details) (USD $) In Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010
Customer Resale Agreements [Member]
Gains (losses) on fair value option	$ 1	[1]	$ 6	[1]	$ (6)	[1]	$ 14	[1]
Residential Mortgage Backed Agency Hybrid Securities [Member]
Gains (losses) on fair value option	27	[1],[2]			24	[1],[2]
Commercial Mortgage Loans Held for Sale [Member]
Gains (losses) on fair value option	4	[1]	11	[1]	3	[1]	33	[1]
Residential Mortgage Loans Held For Sale [Member]
Gains (losses) on fair value option	77	[1]	80	[1]	185	[1]	220	[1]
Residential Mortgage Loans Portfolio [Member]
Gains (losses) on fair value option	(16)	[1]	(1)	[1]	(14)	[1]	2	[1]
Black Rock Series C Preferred Stock [Member]
Gains (losses) on fair value option	$ (80)	[1]	$ 56	[1]	$ (50)	[1]	$ (128)	[1]

[1] The impact on earnings of offsetting hedged items or hedging instruments is not reflected in these amounts.

[2] These residential mortgage-backed agency hybrid securities are carried as Trading securities.