Investment Securities (Narrative) (Details) (USD $)	1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 12, 2014	Jun. 30, 2014 Securities	Mar. 31, 2014	Jun. 30, 2014 Securities	Dec. 31, 2013 Securities
Investment [Line Items]
Number of HTM investment securities in an unrealized loss position		72		72	157
Number of AFS investment securities in an unrealized loss position		338		338	317
Carrying value of pledged securities		$ 1,400,000,000		$ 1,400,000,000	$ 1,500,000,000
Par Value of CDO Securities Sold	631,000,000	25,000,000	993,000,000
Net Gains on Sales of CDOs		5,000,000	31,000,000
Par Amount of Primarily Insurance CDOs Sold				$ 301,000,000