Loans - Carrying Amount of Purchased Credit Impaired Loans (Details) - USD ($) $ in Thousands |
Sep. 30, 2017 |
Dec. 31, 2016 |
|---|---|---|
| Accounts Notes And Loans Receivable [Line Items] | ||
| Total impaired loans | $ 2,701 | $ 4,570 |
| Unaccreted discount on purchased credit impaired loans | (884) | (1,197) |
| Receivables Acquired with Deteriorated Credit Quality | ||
| Accounts Notes And Loans Receivable [Line Items] | ||
| Total | 1,817 | 3,373 |
| Commercial and Industrial Loans | ||
| Accounts Notes And Loans Receivable [Line Items] | ||
| Total impaired loans | 2,416 | 4,258 |
| Commercial and Industrial Loans | Receivables Acquired with Deteriorated Credit Quality | ||
| Accounts Notes And Loans Receivable [Line Items] | ||
| Total | 1,652 | 3,196 |
| Consumer Loans | ||
| Accounts Notes And Loans Receivable [Line Items] | ||
| Total impaired loans | 17 | |
| Real Estate Loans | ||
| Accounts Notes And Loans Receivable [Line Items] | ||
| Total impaired loans | $ 285 | $ 295 |