Investment Securities (Narrative) (Details) (USD $)	0 Months Ended		1 Months Ended	3 Months Ended
	Feb. 12, 2014	Dec. 31, 2013 Securities	Feb. 12, 2014	Mar. 31, 2014 Securities
Investment [Line Items]
Number of HTM investment securities in an unrealized loss position		157		126
Number of AFS investment securities in an unrealized loss position		317		334
Carrying value of pledged securities		$ 1,500,000,000		$ 1,500,000,000
Par Value of CDO Securities Sold			631,000,000	993,000,000
Proceeds from CDOs Sold				607,000,000
Gains on Paydowns of CDOs				5,000,000
Net Gains on Sales of CDOs				31,000,000
Available-for-sale Securities, Gross Realized Gains	65,000,000
Par Amount of Primarily Insurance CDOs Sold				301,000,000
Realized Losses on Sales of CDOs				39,000,000
Unrealized Losses on CDOs		$ 65,000,000