Fair Value Measurements, Quantitative Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($)
Impaired Loans [Member] | Commercial Real Estate [Member] | Income Approach [Member]
Quantitative Information [Abstract]
Fair value	$ 2,539
Unobservable inputs	Capitalization Rate
Impaired Loans [Member] | Commercial Real Estate [Member] | Income Approach [Member] | Minimum [Member]
Quantitative Information [Abstract]
Capitalization rate	3.25%
Impaired Loans [Member] | Commercial Real Estate [Member] | Income Approach [Member] | Maximum [Member]
Quantitative Information [Abstract]
Capitalization rate	3.25%
Impaired Loans [Member] | Commercial Real Estate [Member] | Income Approach [Member] | Weighted Average [Member]
Quantitative Information [Abstract]
Capitalization rate	3.25%
Impaired Loans [Member] | Residential 1st Mortgage [Member] | Sales Comparison Approach [Member]
Quantitative Information [Abstract]
Fair value	$ 389
Unobservable inputs	Adjustment for Difference Between Comparable Sales
Impaired Loans [Member] | Residential 1st Mortgage [Member] | Sales Comparison Approach [Member] | Minimum [Member]
Quantitative Information [Abstract]
Adjustment for difference between comparable sales	2.00%
Impaired Loans [Member] | Residential 1st Mortgage [Member] | Sales Comparison Approach [Member] | Maximum [Member]
Quantitative Information [Abstract]
Adjustment for difference between comparable sales	4.00%
Impaired Loans [Member] | Residential 1st Mortgage [Member] | Sales Comparison Approach [Member] | Weighted Average [Member]
Quantitative Information [Abstract]
Adjustment for difference between comparable sales	3.00%
Impaired Loans [Member] | Home Equity Lines and Loans [Member] | Sales Comparison Approach [Member]
Quantitative Information [Abstract]
Fair value	$ 82
Unobservable inputs	Adjustment for Difference Between Comparable Sales
Impaired Loans [Member] | Home Equity Lines and Loans [Member] | Sales Comparison Approach [Member] | Minimum [Member]
Quantitative Information [Abstract]
Adjustment for difference between comparable sales	1.00%
Impaired Loans [Member] | Home Equity Lines and Loans [Member] | Sales Comparison Approach [Member] | Maximum [Member]
Quantitative Information [Abstract]
Adjustment for difference between comparable sales	2.00%
Impaired Loans [Member] | Home Equity Lines and Loans [Member] | Sales Comparison Approach [Member] | Weighted Average [Member]
Quantitative Information [Abstract]
Adjustment for difference between comparable sales	1.00%
Impaired Loans [Member] | Agricultural [Member] | Income Approach [Member]
Quantitative Information [Abstract]
Fair value	$ 307
Unobservable inputs	Capitalization Rate
Impaired Loans [Member] | Agricultural [Member] | Income Approach [Member] | Minimum [Member]
Quantitative Information [Abstract]
Capitalization rate	6.25%
Impaired Loans [Member] | Agricultural [Member] | Income Approach [Member] | Maximum [Member]
Quantitative Information [Abstract]
Capitalization rate	6.25%
Impaired Loans [Member] | Agricultural [Member] | Income Approach [Member] | Weighted Average [Member]
Quantitative Information [Abstract]
Capitalization rate	6.25%
Impaired Loans [Member] | Agricultural [Member] | Collateral Approach [Member]
Quantitative Information [Abstract]
Fair value	$ 60
Unobservable inputs	Collateral Value
Impaired Loans [Member] | Agricultural [Member] | Collateral Approach [Member] | Minimum [Member]
Quantitative Information [Abstract]
Collateral value	10.00%
Impaired Loans [Member] | Agricultural [Member] | Collateral Approach [Member] | Maximum [Member]
Quantitative Information [Abstract]
Collateral value	10.00%
Impaired Loans [Member] | Agricultural [Member] | Collateral Approach [Member] | Weighted Average [Member]
Quantitative Information [Abstract]
Collateral value	10.00%
Impaired Loans [Member] | Commercial [Member] | Income Approach [Member]
Quantitative Information [Abstract]
Fair value	$ 1,365
Unobservable inputs	Capitalization Rate
Impaired Loans [Member] | Commercial [Member] | Income Approach [Member] | Minimum [Member]
Quantitative Information [Abstract]
Capitalization rate	3.25%
Impaired Loans [Member] | Commercial [Member] | Income Approach [Member] | Maximum [Member]
Quantitative Information [Abstract]
Capitalization rate	3.25%
Impaired Loans [Member] | Commercial [Member] | Income Approach [Member] | Weighted Average [Member]
Quantitative Information [Abstract]
Capitalization rate	3.25%
Other Real Estate [Member] | Home Equity Lines and Loans [Member] | Sales Comparison Approach [Member]
Quantitative Information [Abstract]
Fair value	$ 685
Unobservable inputs	Adjustment for Difference Between Comparable Sales
Other Real Estate [Member] | Home Equity Lines and Loans [Member] | Sales Comparison Approach [Member] | Minimum [Member]
Quantitative Information [Abstract]
Adjustment for difference between comparable sales	10.00%
Other Real Estate [Member] | Home Equity Lines and Loans [Member] | Sales Comparison Approach [Member] | Maximum [Member]
Quantitative Information [Abstract]
Adjustment for difference between comparable sales	10.00%
Other Real Estate [Member] | Home Equity Lines and Loans [Member] | Sales Comparison Approach [Member] | Weighted Average [Member]
Quantitative Information [Abstract]
Adjustment for difference between comparable sales	10.00%
Other Real Estate [Member] | Real Estate Construction [Member] | Sales Comparison Approach [Member]
Quantitative Information [Abstract]
Fair value	$ 1,467
Unobservable inputs	Adjustment for Difference Between Comparable Sales
Other Real Estate [Member] | Real Estate Construction [Member] | Sales Comparison Approach [Member] | Minimum [Member]
Quantitative Information [Abstract]
Adjustment for difference between comparable sales	10.00%
Other Real Estate [Member] | Real Estate Construction [Member] | Sales Comparison Approach [Member] | Maximum [Member]
Quantitative Information [Abstract]
Adjustment for difference between comparable sales	10.00%
Other Real Estate [Member] | Real Estate Construction [Member] | Sales Comparison Approach [Member] | Weighted Average [Member]
Quantitative Information [Abstract]
Adjustment for difference between comparable sales	10.00%