Investment Securities (Cash Flow Model Inputs Used To Calculate Credit Losses) (Details)	Mar. 31, 2014
Significant Inputs Range, Minimum [Member]
Investment [Line Items]
Prepayment CPR	0.00%
Projected cumulative default	18.00%
Credit support	0.00%
Loss severity	20.00%
Significant Inputs Range, Maximum [Member]
Investment [Line Items]
Prepayment CPR	25.00%
Projected cumulative default	56.00%
Credit support	14.00%
Loss severity	81.00%