Loans and Credit Quality - Newly Restructured Loans by Concession (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019 USD ($) contract	Jun. 30, 2018 USD ($) contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification, number of contracts | contract	6	6
Pre-modification, total modification	$ 2,051	$ 4,398
Post-modification, number of contracts | contract	6	6
Post-modification, total modification	$ 1,968	$ 3,432
Commercial | AQR Substandard
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification, number of contracts | contract	5	4
Pre-modification, total modification	$ 1,859	$ 2,704
Post-modification, number of contracts | contract	5	4
Post-modification, total modification	$ 1,779	$ 1,738
Real estate term owner occupied | AQR Substandard
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification, number of contracts | contract	1	2
Pre-modification, total modification	$ 192	$ 1,694
Post-modification, number of contracts | contract	1	2
Post-modification, total modification	$ 189	$ 1,694
Rate Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification, total modification	0	0
Post-modification, total modification	0	0
Rate Modification | Commercial | AQR Substandard
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification, total modification	0	0
Post-modification, total modification	0	0
Rate Modification | Real estate term owner occupied | AQR Substandard
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification, total modification	0	0
Post-modification, total modification	0	0
Term Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification, total modification	0	0
Post-modification, total modification	0	0
Term Modification | Commercial | AQR Substandard
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification, total modification	0	0
Post-modification, total modification	0	0
Term Modification | Real estate term owner occupied | AQR Substandard
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification, total modification	0	0
Post-modification, total modification	0	0
Payment Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification, total modification	701	4,398
Post-modification, total modification	622	3,432
Payment Modification | Commercial | AQR Substandard
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification, total modification	509	2,704
Post-modification, total modification	433	1,738
Payment Modification | Real estate term owner occupied | AQR Substandard
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification, total modification	192	1,694
Post-modification, total modification	189	1,694
Combination Modification
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification, total modification	1,350	0
Post-modification, total modification	1,346	0
Combination Modification | Commercial | AQR Substandard
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification, total modification	1,350	0
Post-modification, total modification	1,346	0
Combination Modification | Real estate term owner occupied | AQR Substandard
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification, total modification	0	0
Post-modification, total modification	$ 0	$ 0