Derivatives and Hedging Activities (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2013 Government Agency Issued Bonds or MBS [Member]	Dec. 31, 2012 Government Agency Issued Bonds or MBS [Member]	Mar. 31, 2012 Government Agency Issued Bonds or MBS [Member]
Derivative [Line Items]
Collateral Already Posted, Aggregate Fair Value		$ 100.4	$ 96.5	$ 100.3
Term of written loan commitments, days	60
Default Assumptions Percentage	100.00%
Maximum value of the guaranteed derivative instruments	4.3
Collateral posted against derivative liabilities		$ 100.4	$ 96.5	$ 100.3
Remaining Term on Swap Participation Agreements, Min	1 year
Remaining Term on Swap Participation Agreements, Max	10 years