Short-term borrowings (Details 1) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Summary of securities sold under agreements to repurchase | |||
| Average balance during the year | $ 71,779 | $ 71,573 | $ 90,951 |
| Average interest rate during the year | 0.07% | 0.04% | 0.04% |
| Maximum month-end balance during the year | $ 89,574 | $ 78,972 | $ 100,462 |
| Weighted average year-end interest rate | 0.06% | 0.06% | 0.06% |
| Balance at year-end | $ 75,482 | $ 58,786 | $ 75,267 |