Allowance for Credit Losses and Credit Quality - Summary of Defaulted TDR Loans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Financing Receivable, Troubled Debt Restructuring [Line Items]
Defaulted TDR loan balance modified during the period	$ 3,172	$ 689
Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Defaulted TDR loan balance modified during the period	2,743	0
Commercial | Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Defaulted TDR loan balance modified during the period	1,515	0
Commercial | Commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Defaulted TDR loan balance modified during the period	1,228	0
Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Defaulted TDR loan balance modified during the period	429	689
Consumer | Residential mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Defaulted TDR loan balance modified during the period	197	630
Consumer | Home equity
Financing Receivable, Troubled Debt Restructuring [Line Items]
Defaulted TDR loan balance modified during the period	198	59
Consumer | Consumer installment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Defaulted TDR loan balance modified during the period	$ 34	$ 0