v3.8.0.1
Loans - Composition of TDRs by Accrual and Nonaccrual Status (Details) - USD ($)
$ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Accounts Notes And Loans Receivable [Line Items]    
Troubled Debt Restructurings, Nonaccrual $ 11,359 $ 8,238
Troubled Debt Restructurings, Total 4,500 3,400
Commercial and Industrial Loans    
Accounts Notes And Loans Receivable [Line Items]    
Troubled Debt Restructurings, Nonaccrual 9,617 3,359
Principal Reduction and Extended Maturity | Commercial and Industrial Loans    
Accounts Notes And Loans Receivable [Line Items]    
Troubled Debt Restructurings, Accrual 195 317
Troubled Debt Restructurings, Nonaccrual 4,296 3,109
Troubled Debt Restructurings, Total $ 4,491 $ 3,426