Loans - Deferrals (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) security	Sep. 30, 2019 security loan	Sep. 30, 2020 USD ($) security	Sep. 30, 2019 loan	Jun. 30, 2020 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Deferrals	0	0
Payment Deferral | COVID-19 Modification
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferrals Balance | $	$ 23,264		$ 23,264		$ 392,430
Number of Deferrals			52
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Deferrals | loan		4		4
Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Deferrals			1
Commercial Portfolio Segment | Payment Deferral | COVID-19 Modification
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferrals Balance | $	20,303		$ 20,303		384,108
Number of Deferrals			26
Commercial Portfolio Segment | Commercial and industrial | Payment Deferral | COVID-19 Modification
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferrals Balance | $	722		$ 722		2,312
Number of Deferrals			5
Commercial Portfolio Segment | Owner-occupied commercial real estate | Payment Deferral | COVID-19 Modification
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferrals Balance | $	6,235		$ 6,235		25,254
Number of Deferrals			4
Commercial Portfolio Segment | Investor commercial real estate | Payment Deferral | COVID-19 Modification
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferrals Balance | $	0		$ 0		411
Number of Deferrals			0
Commercial Portfolio Segment | Construction | Payment Deferral | COVID-19 Modification
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferrals Balance | $	0		$ 0		0
Number of Deferrals			0
Commercial Portfolio Segment | Single tenant lease financing | Payment Deferral | COVID-19 Modification
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferrals Balance | $	8,281		$ 8,281		275,129
Number of Deferrals			4
Commercial Portfolio Segment | Public finance | Payment Deferral | COVID-19 Modification
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferrals Balance | $	0		$ 0		0
Number of Deferrals			0
Commercial Portfolio Segment | Healthcare finance | Payment Deferral | COVID-19 Modification
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferrals Balance | $	2,275		$ 2,275		79,179
Number of Deferrals			3
Commercial Portfolio Segment | Small Business Lending [Member] | Payment Deferral | COVID-19 Modification
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferrals Balance | $	2,790		$ 2,790		1,823
Number of Deferrals			10
Consumer Portfolio | Payment Deferral | COVID-19 Modification
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferrals Balance | $	2,961		$ 2,961		8,322
Number of Deferrals			26
Consumer Portfolio | Residential mortgage | Payment Deferral | COVID-19 Modification
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferrals Balance | $	2,329		$ 2,329		4,719
Number of Deferrals			5
Consumer Portfolio | Home equity | Payment Deferral | COVID-19 Modification
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferrals Balance | $	0		$ 0		398
Number of Deferrals			0
Consumer Portfolio | Other consumer | Payment Deferral | COVID-19 Modification
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferrals Balance | $	$ 632		$ 632		$ 3,205
Number of Deferrals			21