Derivative Financial Instruments (Narrative)(Details) (USD $)
9 Months Ended
Sep. 30, 2012
Dec. 31, 2011
Jul. 31, 2009
Cash Flow Hedge [Member]
Sep. 30, 2012
Derivative Matured [Member]
Derivative [Line Items]        
Interest rate swap notional amount $ 15,000,000   $ 20,000,000 $ 5,000,000
Number of interest rate swap contracts 3      
Derivative, Maturity Date Jun. 15, 2012      
Interest rate swap fair value (946,000) (1,000,000)    
Cash collateral 1,400,000      
Gain on derivative 8,000      
Deferred tax asset on gain on derivative $ 36,000      
Cash flow hedge ineffectiveness 0