Deposits (Details) - USD ($) $ in Thousands |
Mar. 31, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Deposits [Abstract] | ||
| Time deposits, greater than $250,000 | $ 51,300 | $ 45,900 |
| Summary of the contractual maturities of time deposits [Abstract] | ||
| Within one year | 522,568 | |
| More than one to two years | 155,048 | |
| More than two to three years | 15,534 | |
| More than three to four years | 1,129 | |
| More than four through five years | 2,919 | |
| Time deposits | $ 697,198 | $ 688,979 |