Time deposits (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Time Deposits, Fiscal Year Maturity [Abstract]    
2015 $ 148,164  
2016 49,422  
2017 25,017  
2018 9,111  
2019 5,273  
Thereafter 151  
Total $ 237,138 $ 141,315