Fair Value Measurements, Assets or Liabilities Measured at Fair Value on a Non-recurring Basis (Details) - Nonrecurring [Member] - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	$ 5,658	$ 5,732	$ 5,621
Other Real Estate	873	873	873
Total Assets Measured at Fair Value On a Non-Recurring Basis	6,531	6,605	6,494
Commercial Real Estate [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	2,587	2,658	2,596
Residential 1st Mortgage [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	1,518	1,550	1,476
Home Equity Lines and Loans [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	66	70	71
Agricultural [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	97
Commercial [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	1,390	1,454	1,478
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	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
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	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	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
Other Observable Inputs (Level 2) [Member] | Commercial [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	0	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	5,658	5,732	5,621
Other Real Estate	873	873	873
Total Assets Measured at Fair Value On a Non-Recurring Basis	6,531	6,605	6,494
Significant Unobservable Inputs (Level 3) [Member] | Commercial Real Estate [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	2,587	2,658	2,596
Significant Unobservable Inputs (Level 3) [Member] | Residential 1st Mortgage [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	1,518	1,550	1,476
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	66	70	71
Significant Unobservable Inputs (Level 3) [Member] | Agricultural [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	97
Significant Unobservable Inputs (Level 3) [Member] | Commercial [Member]
Fair Value on Non-recurring Basis by Fair Value Hierarchy [Abstract]
Impaired Loans	1,390	1,454	1,478
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