Allowance for Credit Losses and Allowance for Unfunded Commitments and Letters of Credit (Changes in the Allowance for Unfunded Commitments and Letters of Credit) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Schedule of Allowance for Unfunded Commitments and Letters of Credit [Line Items]
Allowance For Unfunded Loan Commitments And Letters Of Credit	$ 9,800	$ 6,000	$ 8,300	$ 3,430
Allowance for Loan and Lease Losses, Net Changes In Unfunded Commitments and Letters Of Credit Allowance	$ 1,500	$ 1,000
Accounting Standards Update 2016-13 [Member]
Schedule of Allowance for Unfunded Commitments and Letters of Credit [Line Items]
Change in allowance for unfunded commitments and letters of credit due to adoption of new ASU			$ 0	$ 1,570