Loans - Nonaccrual Loans and Loans Past Due over 90 Days Still Accruing Interest by Class of Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Nonaccrual	$ 31,854	$ 21,736
Past Due Over 90 Days Still on Accrual	33	61
Commercial, industrial and agricultural
Financing Receivable, Past Due [Line Items]
Nonaccrual	12,144	11,644
Past Due Over 90 Days Still on Accrual	16	0
Commercial mortgages
Financing Receivable, Past Due [Line Items]
Nonaccrual	14,237	4,533
Past Due Over 90 Days Still on Accrual	0	0
Residential real estate
Financing Receivable, Past Due [Line Items]
Nonaccrual	4,663	4,724
Past Due Over 90 Days Still on Accrual	0	59
Consumer
Financing Receivable, Past Due [Line Items]
Nonaccrual	810	835
Past Due Over 90 Days Still on Accrual	0	0
Credit Cards
Financing Receivable, Past Due [Line Items]
Nonaccrual	0	0
Past Due Over 90 Days Still on Accrual	$ 17	$ 2