Investment Securities (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2013
Schedule of Investments [Line Items]
Asset backed securities mortgage portfolio, term	15 years
U.S. Treasury And Sponsored Entities Callable Notes [Member]
Schedule of Investments [Line Items]
Available for Sale expected to be called	303.8
Available-for-sale securities	570.6
U.S. Treasury And Sponsored Entities Callable Notes [Member] \| Minimum [Member]
Schedule of Investments [Line Items]
Residential mortgage-backed securities and collateralized mortgage obligations, term	10 years
U.S. Treasury And Sponsored Entities Callable Notes [Member] \| Maximum [Member]
Schedule of Investments [Line Items]
Residential mortgage-backed securities and collateralized mortgage obligations, term	14 years
U.S. Government Sponsored Entities Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Proceeds from Sale of Available-for-sale Securities, Debt	0
U.S. Government Sponsored Entities Asset-Backed Securities [Member] \| Maximum [Member]
Schedule of Investments [Line Items]
Residential mortgage-backed securities and collateralized mortgage obligations, term	15 years

Amount of debt securities categorized neither as held-to-maturity nor trading.

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+ Details

- Definition

The cash inflow associated with the sale of debt securities classified as available-for-sale securities.

+ References

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+ Details