Loans and Loans Held for Sale - Summary of Restructured Loans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans	$ 1,377	$ 1,303	$ 8,159	$ 7,852
Commercial real estate | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans	0	0	0	2,210
Commercial and industrial | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans	0	75	6,229	2,143
Commercial construction | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans	0	701	0	2,572
Business banking | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans	1,130	27	1,210	27
Consumer real estate | Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans	247	500	720	900
Other consumer | Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans	$ 0	$ 0	0	$ 0
Total TDRs
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			34,971		$ 46,748
Total TDRs | Commercial real estate | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			6,418		16,668
Total TDRs | Commercial and industrial | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			14,763		16,975
Total TDRs | Commercial construction | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			3,222		3,267
Total TDRs | Business banking | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			2,947		1,933
Total TDRs | Consumer real estate | Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			7,617		7,900
Total TDRs | Other consumer | Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			4		5
Performing TDRs
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			14,321		17,460
Performing TDRs | Commercial real estate | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			4		14
Performing TDRs | Commercial and industrial | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			3,579		7,090
Performing TDRs | Commercial construction | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			3,222		3,267
Performing TDRs | Business banking | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			1,439		1,503
Performing TDRs | Consumer real estate | Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			6,073		5,581
Performing TDRs | Other consumer | Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			4		5
Nonperforming TDRs
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			20,650		29,288
Nonperforming TDRs | Commercial real estate | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			6,415		16,654
Nonperforming TDRs | Commercial and industrial | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			11,183		9,885
Nonperforming TDRs | Commercial construction | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			0		0
Nonperforming TDRs | Business banking | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			1,508		430
Nonperforming TDRs | Consumer real estate | Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			1,544		2,319
Nonperforming TDRs | Other consumer | Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Restructured loans			$ 0		$ 0