Investment securities available for sale (Details Textual) - USD ($)
3 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]      
Pledged Assets Separately Reported, Securities Pledged for Repurchase Agreements, at Fair Value $ 5,156,000   $ 5,968,000
Proceeds from Sale of Available-for-sale Securities, Debt 11,000,000 $ 7,000,000  
Available-for-sale Securities, Gross Realized Gain (Loss) $ 109,000 $ 7,000