Fair Value Measurements, Assets or Liabilities Measured at Fair Value on a Non-recurring Basis (Details) - Nonrecurring [Member] - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	$ 1,893	$ 1,509
Other Real Estate	3,745	2,441
Total Assets Measured at Fair Value On a Non-Recurring Basis	5,638	3,950
Residential 1st Mortgages [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	480	329
Home Equity Lines and Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	83	125
Other Real Estate	785
Agricultural [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	497	298
Commercial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	833	752
Consumer [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans		5
Real Estate Construction [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Real Estate	2,960	2,441
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	0	0
Other Real Estate	0	0
Total Assets Measured at Fair Value On a Non-Recurring Basis	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Residential 1st Mortgages [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Home Equity Lines and Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	0	0
Other Real Estate	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Agricultural [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Commercial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Consumer [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Real Estate Construction [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Real Estate	0	0
Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	0	0
Other Real Estate	0	0
Total Assets Measured at Fair Value On a Non-Recurring Basis	0	0
Other Observable Inputs (Level 2) [Member] | Residential 1st Mortgages [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	0	0
Other Observable Inputs (Level 2) [Member] | Home Equity Lines and Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	0	0
Other Real Estate	0
Other Observable Inputs (Level 2) [Member] | Agricultural [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	0	0
Other Observable Inputs (Level 2) [Member] | Commercial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	0	0
Other Observable Inputs (Level 2) [Member] | Consumer [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans		0
Other Observable Inputs (Level 2) [Member] | Real Estate Construction [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Real Estate	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	1,893	1,509
Other Real Estate	3,745	2,441
Total Assets Measured at Fair Value On a Non-Recurring Basis	5,638	3,950
Significant Unobservable Inputs (Level 3) [Member] | Residential 1st Mortgages [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	480	329
Significant Unobservable Inputs (Level 3) [Member] | Home Equity Lines and Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	83	125
Other Real Estate	785
Significant Unobservable Inputs (Level 3) [Member] | Agricultural [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	497	298
Significant Unobservable Inputs (Level 3) [Member] | Commercial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans	833	752
Significant Unobservable Inputs (Level 3) [Member] | Consumer [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired Loans		5
Significant Unobservable Inputs (Level 3) [Member] | Real Estate Construction [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Real Estate	$ 2,960	$ 2,441