Loans and Allowance (Non-Accrual Loan, Segregated by Class of Loans) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 5,220	$ 5,144
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	1,107	912
First Mortgage [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	3,409	3,626
Second Mortgage [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	309	335
Automobile Loan [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	22	5
Boat/RVs [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	198	224
Other [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	16	24
Commercial and Industrial [Member] | Commercial Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 159	$ 18