Allowance for Credit Losses - Amortized Cost Basis of Revolving Loans that Were Converted to Term Loans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Credit quality
Total Revolving Loans Converted to Term Loans During the Period	$ 1,801	$ 28,524
Commercial and Industrial
Credit quality
Total Revolving Loans Converted to Term Loans During the Period	229	28,228
Home equity Line
Credit quality
Total Revolving Loans Converted to Term Loans During the Period	1,079
Consumer
Credit quality
Total Revolving Loans Converted to Term Loans During the Period	$ 493
Residential Mortgage.
Credit quality
Total Revolving Loans Converted to Term Loans During the Period		$ 296