Fair Value Measurements, Assets or Liabilities Measured at Fair Value on a Non-recurring Basis (Details) - Nonrecurring [Member] - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	$ 1,669	$ 5,751	$ 5,789
Other Real Estate	873	873	873
Total Assets Measured at Fair Value On a Non-Recurring Basis	2,542	6,624	6,662
Commercial Real Estate [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans		2,588	2,660
Residential 1st Mortgage [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	1,470	1,403	1,540
Home Equity Lines and Loans [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	64	142	69
Agricultural [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans		88	102
Commercial [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans		1,391	1,418
Consumer [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	135	139
Real Estate Construction [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Other Real Estate	873	873	873
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	0	0	0
Other Real Estate	0	0	0
Total Assets Measured at Fair Value On a Non-Recurring Basis	0	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Commercial Real Estate [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Residential 1st Mortgage [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	0	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Home Equity Lines and Loans [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	0	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Agricultural [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Commercial [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Consumer [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Real Estate Construction [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Other Real Estate	0	0	0
Other Observable Inputs (Level 2) [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	0	0	0
Other Real Estate	0	0	0
Total Assets Measured at Fair Value On a Non-Recurring Basis	0	0	0
Other Observable Inputs (Level 2) [Member] | Commercial Real Estate [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans		0	0
Other Observable Inputs (Level 2) [Member] | Residential 1st Mortgage [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	0	0	0
Other Observable Inputs (Level 2) [Member] | Home Equity Lines and Loans [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	0	0	0
Other Observable Inputs (Level 2) [Member] | Agricultural [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans		0	0
Other Observable Inputs (Level 2) [Member] | Commercial [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans		0	0
Other Observable Inputs (Level 2) [Member] | Consumer [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	0	0
Other Observable Inputs (Level 2) [Member] | Real Estate Construction [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Other Real Estate	0	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	1,669	5,751	5,789
Other Real Estate	873	873	873
Total Assets Measured at Fair Value On a Non-Recurring Basis	2,542	6,624	6,662
Significant Unobservable Inputs (Level 3) [Member] | Commercial Real Estate [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans		2,588	2,660
Significant Unobservable Inputs (Level 3) [Member] | Residential 1st Mortgage [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	1,470	1,403	1,540
Significant Unobservable Inputs (Level 3) [Member] | Home Equity Lines and Loans [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	64	142	69
Significant Unobservable Inputs (Level 3) [Member] | Agricultural [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans		88	102
Significant Unobservable Inputs (Level 3) [Member] | Commercial [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans		1,391	1,418
Significant Unobservable Inputs (Level 3) [Member] | Consumer [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	135	139
Significant Unobservable Inputs (Level 3) [Member] | Real Estate Construction [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Other Real Estate	$ 873	$ 873	$ 873