Loans and Allowance for Loan Losses (Schedule of Aging of Loans Receivable) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 1,383	$ 1,818
Current	625,409	594,492
Total Loans Receivable	626,792	596,310
Loans Receivable - Greater than 90 Days and Accruing	349	440
1-4 Family Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans Receivable	193,154	176,971
Commercial real estate [Member] | Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	255	372
Current	91,301	89,700
Total Loans Receivable	91,556	90,072
Loans Receivable - Greater than 90 Days and Accruing
Commercial real estate [Member] | Agricultural Sector [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	263
Current	152,771	152,050
Total Loans Receivable	153,034	152,050
Loans Receivable - Greater than 90 Days and Accruing
Commercial real estate [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due
Current	18,217	18,670
Total Loans Receivable	18,217	18,670
Loans Receivable - Greater than 90 Days and Accruing
Consumer Real Estate [Member] | 1-4 Family Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	597	1,176
Current	192,557	175,795
Total Loans Receivable	193,154	176,971
Loans Receivable - Greater than 90 Days and Accruing	318	395
Consumer Real Estate [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	45	40
Current	10,139	11,141
Total Loans Receivable	10,184	11,181
Loans Receivable - Greater than 90 Days and Accruing
Consumer Real Estate [Member] | Home equity lines of credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	29	30
Current	62,907	61,074
Total Loans Receivable	62,936	61,104
Loans Receivable - Greater than 90 Days and Accruing	29	30
Commercial and Industrial Sector [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	30	174
Current	47,487	41,252
Total Loans Receivable	47,517	41,426
Loans Receivable - Greater than 90 Days and Accruing
Commercial and Industrial Sector [Member] | Tax-free loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due
Current	21,770	20,722
Total Loans Receivable	21,770	20,722
Loans Receivable - Greater than 90 Days and Accruing
Commercial and Industrial Sector [Member] | Agriculture loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	145
Current	18,064	18,794
Total Loans Receivable	18,209	18,794
Loans Receivable - Greater than 90 Days and Accruing
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	19	26
Current	10,196	5,294
Total Loans Receivable	10,215	5,320
Loans Receivable - Greater than 90 Days and Accruing	2	15
30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	548	646
30-59 Days Past Due [Member] | Commercial real estate [Member] | Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due
30-59 Days Past Due [Member] | Commercial real estate [Member] | Agricultural Sector [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	263
30-59 Days Past Due [Member] | Commercial real estate [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due
30-59 Days Past Due [Member] | Consumer Real Estate [Member] | 1-4 Family Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	183	533
30-59 Days Past Due [Member] | Consumer Real Estate [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	45	40
30-59 Days Past Due [Member] | Consumer Real Estate [Member] | Home equity lines of credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due
30-59 Days Past Due [Member] | Commercial and Industrial Sector [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	30	65
30-59 Days Past Due [Member] | Commercial and Industrial Sector [Member] | Tax-free loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due
30-59 Days Past Due [Member] | Commercial and Industrial Sector [Member] | Agriculture loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	10
30-59 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	17	8
60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	231	360
60-89 Days Past Due [Member] | Commercial real estate [Member] | Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due
60-89 Days Past Due [Member] | Commercial real estate [Member] | Agricultural Sector [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due
60-89 Days Past Due [Member] | Commercial real estate [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due
60-89 Days Past Due [Member] | Consumer Real Estate [Member] | 1-4 Family Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	96	248
60-89 Days Past Due [Member] | Consumer Real Estate [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due
60-89 Days Past Due [Member] | Consumer Real Estate [Member] | Home equity lines of credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due
60-89 Days Past Due [Member] | Commercial and Industrial Sector [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		109
60-89 Days Past Due [Member] | Commercial and Industrial Sector [Member] | Tax-free loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due
60-89 Days Past Due [Member] | Commercial and Industrial Sector [Member] | Agriculture loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	135
60-89 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due		3
Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	604	812
Greater than 90 Days Past Due [Member] | Commercial real estate [Member] | Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	255	372
Greater than 90 Days Past Due [Member] | Commercial real estate [Member] | Agricultural Sector [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due
Greater than 90 Days Past Due [Member] | Commercial real estate [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due
Greater than 90 Days Past Due [Member] | Consumer Real Estate [Member] | 1-4 Family Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	318	395
Greater than 90 Days Past Due [Member] | Consumer Real Estate [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due
Greater than 90 Days Past Due [Member] | Consumer Real Estate [Member] | Home equity lines of credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	29	30
Greater than 90 Days Past Due [Member] | Commercial and Industrial Sector [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due
Greater than 90 Days Past Due [Member] | Commercial and Industrial Sector [Member] | Tax-free loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due
Greater than 90 Days Past Due [Member] | Commercial and Industrial Sector [Member] | Agriculture loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due
Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 2	$ 15