Allowance for Credit Losses - Amortized Cost Basis of Revolving Loans that Were Converted to Term Loans (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020
Credit quality
Total Revolving Loans Converted to Term Loans During the Period	$ 8,848	$ 41,594
Commercial and Industrial
Credit quality
Total Revolving Loans Converted to Term Loans During the Period	5	28,527
Home equity Line
Credit quality
Total Revolving Loans Converted to Term Loans During the Period	$ 8,843	12,771
Residential Mortgage.
Credit quality
Total Revolving Loans Converted to Term Loans During the Period		$ 296