Commitments, Contingencies and Credit Risk (Details) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Credit Commitments and Contingencies      
Liabilities for potential obligations under guarantees $ 0 $ 0  
Lease Commitments      
Rent expense under operating leases 1,500,000 1,600,000 2,500,000
Projected minimum rental payments under the terms of leases      
2015 941,000    
2016 219,000    
2017 111,000    
2018 102,000    
2019 70,000    
Total 1,443,000    
Commitments to extend credit      
Credit Commitments and Contingencies      
Financial instruments whose contract amounts represent credit risk 561,439,000 527,614,000  
Standby letters of credit      
Credit Commitments and Contingencies      
Financial instruments whose contract amounts represent credit risk $ 20,466,000 $ 10,155,000  
Maximum      
Credit Commitments and Contingencies      
Term for guarantee 1 year