Commitments and Contingencies - Summary of Contractual Amounts of Off-balance Sheet Financial Instruments (Details) - USD ($) $ in Thousands |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Commitments to Extend Credit [Member] | ||
| Commitments And Contingencies [Line Items] | ||
| Off-balance sheet financial instrument, contractual amount | $ 445,645 | $ 382,928 |
| Stand-by Letters of Credit and Bond Commitments [Member] | ||
| Commitments And Contingencies [Line Items] | ||
| Off-balance sheet financial instrument, contractual amount | 29,332 | 36,333 |
| Unused Credit Card Lines, All Unsecured [Member] | ||
| Commitments And Contingencies [Line Items] | ||
| Off-balance sheet financial instrument, contractual amount | $ 25,803 | $ 25,512 |