Allowance for Credit Losses and Credit Quality - Summary of TDR Modifications (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification Investment	$ 11,110	$ 33,552	$ 18,239	$ 38,010
Post-modification Investment	10,985	33,552	18,089	37,991
Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification Investment	7,504	31,311	10,081	32,505
Post-modification Investment	7,504	31,311	10,081	32,505
Commercial | Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification Investment	4,875	31,311	7,346	32,505
Post-modification Investment	4,875	31,311	7,346	32,505
Commercial | Commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification Investment	2,629	0	2,735	0
Post-modification Investment	2,629	0	2,735	0
Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification Investment	3,606	2,241	8,158	5,505
Post-modification Investment	3,481	2,241	8,008	5,486
Consumer | Residential mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification Investment	2,373	1,107	5,581	2,360
Post-modification Investment	2,373	1,107	5,580	2,353
Consumer | Consumer installment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification Investment	134	257	511	630
Post-modification Investment	67	257	420	630
Consumer | Home equity
Financing Receivable, Troubled Debt Restructuring [Line Items]
Pre-modification Investment	1,099	877	2,066	2,515
Post-modification Investment	$ 1,041	$ 877	$ 2,008	$ 2,503