Loans (Loans Purchased and/or Sold During the Year by Portfolio Segment) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchases	$ 0	$ 0
Sales	0	3,128
Commercial and Industrial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchases	0	0
Sales	0	0
Commercial Real Estate Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchases	0	0
Sales	0	3,128
Agricultural Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchases	0	0
Sales	0	0
Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchases	0	0
Sales	0	0
Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchases	0	0
Sales	0	0
Home Equity Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchases	0	0
Sales	0	0
Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchases	0	0
Sales	0	0
Residential Mortgage Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Purchases	0	0
Sales	$ 0	$ 0