Investment Securities (Details Textual) (USD $) In Billions, unless otherwise specified	Mar. 31, 2013 Security	Dec. 31, 2012	Mar. 31, 2012
Investment Securities [Abstract]
Carrying value of secure public deposits, FHLB advances and other secured borrowings	$ 1.25	$ 1.40	$ 1.38
Number of available for sale securities in unrealized loss position	68
Number of held to maturity securities in unrealized loss position	3

Disclosure regarding factors used to determine that the impairment of securities not categorized as either held-to-maturity securities or trading securities (hence equal to available for sale securities) where cost exceeds fair value is not an other than temporary impairment (OTTI). This item contains disclosure of the number of investment positions in the available-for-sale investments determined to be temporarily impaired.

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Disclosure regarding factors used to determine that the impairment of securities categorized as held-to-maturity where cost exceeds fair value is not an other than temporary impairment (OTTI). This item contains disclosure of the number of investment positions in the held-to-maturity investments determined to be temporarily impaired.

+ References+ Details