Derivatives and Hedging Activities (Details) (Not Designated as Hedging Instrument [Member], Interest Rate Contracts [Member], USD $)	Sep. 30, 2012	Dec. 31, 2011
Derivative [Line Items]
Notional Amount of Interest Rate Derivative Instruments Not Designated as Hedging Instruments	$ 164,300,000	$ 160,300,000
Other Assets [Member]
Derivative [Line Items]
Fair value of asset derivative instruments	16,375,000	16,302,000
Other Liabilities [Member]
Derivative [Line Items]
Fair value of liability derivative instruments	$ 16,375,000	$ 16,302,000