Fair Value of Financial Instruments Fair Value of Financial Instruments 7 (Details) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Fair value of gain (loss) related to mortgage banking activities $ 3,600,000 $ (5,300,000) $ 2,400,000
Overnight repurchase agreements, value of securities pledged 18,800,000 21,200,000  
Overnight repurchase agreements, net 4,700,000 7,000,000  
Maturity Overnight      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Overnight repurchase agreements primarily with commercial customers at an average rate of 0.17% and 0.15% at December 31, 2014 and 2013 $ 14,087,000 $ 14,233,000