Fair Value (Fair Value Option - Changes in Fair Value) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quantifying Misstatement In Current Year Financial Statements Amount		$ 6,200,000,000
Customer Resale Agreements [Member]
Gains (Losses) - FVO: Changes in Fair Value	(3,000,000)	(7,000,000)	(10,000,000)
Residential mortgage-backed agency securities with embedded derivatives [Member]
Gains (Losses) - FVO: Changes in Fair Value			13,000,000
Trading Loans [Member]
Gains (Losses) - FVO: Changes in Fair Value	2,000,000	3,000,000	2,000,000
Loans Held For Sale [Member] | Commercial Mortgage [Member]
Gains (Losses) - FVO: Changes in Fair Value	50,000,000	(10,000,000)	(5,000,000)
Loans Held For Sale [Member] | Residential Mortgage [Member]
Gains (Losses) - FVO: Changes in Fair Value	212,000,000	213,000,000	(223,000,000)
Quantifying Misstatement In Current Year Financial Statements Amount		34,000,000	43,000,000
Loans - Portfolio [Member] | Residential Mortgage [Member]
Gains (Losses) - FVO: Changes in Fair Value	157,000,000	60,000,000	7,000,000
Quantifying Misstatement In Current Year Financial Statements Amount		(33,000,000)	(43,000,000)
BlackRock Series C Preferred Stock
Gains (Losses) - FVO: Changes in Fair Value	43,000,000	122,000,000	33,000,000
Other Borrowed Funds [Member]
Gains (Losses) - FVO: Changes in Fair Value	$ (5,000,000)	$ (9,000,000)