Loans and Credit Quality - Restructured Loans (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Modifications [Line Items]
New Troubled Debt Restructurings	$ 3,432
Existing Troubled Debt Restructurings	20,326
Total	23,758	$ 23,800
Commercial | AQR Substandard
Financing Receivable, Modifications [Line Items]
New Troubled Debt Restructurings	1,738
Real estate term owner occupied | AQR Substandard
Financing Receivable, Modifications [Line Items]
New Troubled Debt Restructurings	1,694
Accrual Status
Financing Receivable, Modifications [Line Items]
New Troubled Debt Restructurings	1,542
Existing Troubled Debt Restructurings	7,554
Total	9,096
Accrual Status | Commercial | AQR Substandard
Financing Receivable, Modifications [Line Items]
New Troubled Debt Restructurings	1,179
Accrual Status | Real estate term owner occupied | AQR Substandard
Financing Receivable, Modifications [Line Items]
New Troubled Debt Restructurings	363
Nonaccrual Status
Financing Receivable, Modifications [Line Items]
New Troubled Debt Restructurings	1,890
Existing Troubled Debt Restructurings	12,772
Total	14,662
Nonaccrual Status | Commercial | AQR Substandard
Financing Receivable, Modifications [Line Items]
New Troubled Debt Restructurings	559
Nonaccrual Status | Real estate term owner occupied | AQR Substandard
Financing Receivable, Modifications [Line Items]
New Troubled Debt Restructurings	$ 1,331