Deposits - Additional Information (Details) - USD ($) $ in Millions |
Sep. 30, 2015 |
Dec. 31, 2014 |
|---|---|---|
| Deposits [Abstract] | ||
| Certificates of deposits of $250,000 or more, maturities within one year | $ 103.8 | $ 96.9 |
| Certificates of deposits of $250,000 or more, maturities after one year | 6.8 | 20.1 |
| Certificates of deposits of $250,000 or more, total | 110.6 | 117.0 |
| Certificates of deposit of less than $ 250,000, maturities within one year | 231.2 | 127.1 |
| Certificates of deposit of less than $ 250,000, maturities after one year | 19.0 | 9.3 |
| Certificates of deposit of less than $250,000, total | $ 250.2 | $ 136.4 |