Fair Value (Assets and Liabilities Measured at Fair Value on Non-Recurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Impaired Loans | Commercial and Industrial Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assets	$ 17	$ 15
Impaired Loans | Commercial Real Estate Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assets	768	960
Impaired Loans | Agricultural Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assets	450
Other Real Estate | Commercial Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assets	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Impaired Loans | Commercial and Industrial Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assets	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Impaired Loans | Commercial Real Estate Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assets	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Impaired Loans | Agricultural Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assets	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Other Real Estate | Commercial Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assets	0	0
Significant Other Observable Inputs (Level 2) | Impaired Loans | Commercial and Industrial Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assets	0	0
Significant Other Observable Inputs (Level 2) | Impaired Loans | Commercial Real Estate Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assets	0	0
Significant Other Observable Inputs (Level 2) | Impaired Loans | Agricultural Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assets	0
Significant Other Observable Inputs (Level 2) | Other Real Estate | Commercial Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assets	0	0
Significant Unobservable Inputs (Level 3) | Impaired Loans | Commercial and Industrial Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assets	17	15
Significant Unobservable Inputs (Level 3) | Impaired Loans | Commercial Real Estate Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assets	768	960
Significant Unobservable Inputs (Level 3) | Impaired Loans | Agricultural Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assets	450
Significant Unobservable Inputs (Level 3) | Other Real Estate | Commercial Real Estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assets	$ 0	$ 0