Investment Securities (Summary Of Investment Securities Available-For-Sale In Unrealized Loss Positions) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Temporarily Impaired Less than 12 months, Fair Value	$ 911		$ 5,825
Temporarily Impaired Less than 12 months, Unrealized Losses	5		187
Temporarily Impaired 12 months or more, Fair Value	3,562		182
Temporarily Impaired 12 months or more, Unrealized Losses	112		12
Temporarily Impaired Total, Fair Value	4,473		6,007
Temporarily Impaired Total, Unrealized Losses	117		199
Residential Mortgage-Backed Securities
Temporarily Impaired Less than 12 months, Fair Value	911	[1]	5,825	[1]
Temporarily Impaired Less than 12 months, Unrealized Losses	5	[1]	187	[1]
Temporarily Impaired 12 months or more, Fair Value	3,408	[1]	11	[1]
Temporarily Impaired 12 months or more, Unrealized Losses	108	[1]	1	[1]
Temporarily Impaired Total, Fair Value	4,319	[1]	5,836	[1]
Temporarily Impaired Total, Unrealized Losses	113	[1]	188	[1]
State And Municipal Securities
Temporarily Impaired Less than 12 months, Fair Value	0	[2]	0	[2]
Temporarily Impaired Less than 12 months, Unrealized Losses	0	[2]	0	[2]
Temporarily Impaired 12 months or more, Fair Value	22	[2]	22	[2]
Temporarily Impaired 12 months or more, Unrealized Losses	1	[2]	2	[2]
Temporarily Impaired Total, Fair Value	22	[2]	22	[2]
Temporarily Impaired Total, Unrealized Losses	1	[2]	2	[2]
Corporate Debt Securities
Temporarily Impaired Less than 12 months, Fair Value	0	[2]	0	[2]
Temporarily Impaired Less than 12 months, Unrealized Losses	0	[2]	0	[2]
Temporarily Impaired 12 months or more, Fair Value	1	[2]	1	[2]
Temporarily Impaired 12 months or more, Unrealized Losses	0	[2],[3]	0	[2],[3]
Temporarily Impaired Total, Fair Value	1	[2]	1	[2]
Temporarily Impaired Total, Unrealized Losses	0	[2],[3]	0	[2],[3]
Equity and Other Non-Debt Securities
Temporarily Impaired Less than 12 months, Fair Value	0	[2]	0	[2]
Temporarily Impaired Less than 12 months, Unrealized Losses	0	[2]	0	[2]
Temporarily Impaired 12 months or more, Fair Value	131	[2]	148	[2]
Temporarily Impaired 12 months or more, Unrealized Losses	3	[2]	9	[2]
Temporarily Impaired Total, Fair Value	131	[2]	148	[2]
Temporarily Impaired Total, Unrealized Losses	$ 3	[2]	$ 9	[2]

[1] Residential mortgage-backed securities issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises.

[2] Auction-rate securities.

[3] Unrealized losses less than $0.5 million.