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