Fair Value (Quantitative Information of Fair Value Measurements) (Details) - Significant Unobservable Inputs (Level 3) - Impaired Loans $ in Thousands	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Commercial and Industrial Loans | Sales comparison approach | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	0.00	0.29
Commercial and Industrial Loans | Sales comparison approach | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	1.00	1.00
Commercial and Industrial Loans | Sales comparison approach | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	0.62	0.64
Commercial Real Estate Loans | Sales comparison approach | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	0.00	0.47
Commercial Real Estate Loans | Sales comparison approach | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	1.00	0.91
Commercial Real Estate Loans | Sales comparison approach | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	0.48	0.64
Agricultural Loans | Sales comparison approach | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	0.30
Agricultural Loans | Sales comparison approach | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	1.00
Agricultural Loans | Sales comparison approach | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	0.64
Home Equity Loans | Sales comparison approach | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	0.09
Home Equity Loans | Sales comparison approach | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	0.09
Home Equity Loans | Sales comparison approach | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	0.09
Residential Mortgage Loans | Sales comparison approach | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	0.66
Residential Mortgage Loans | Sales comparison approach | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	0.87
Residential Mortgage Loans | Sales comparison approach | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	0.81
Fair Value, Measurements, Nonrecurring | Commercial and Industrial Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 2,727	$ 2,109
Fair Value, Measurements, Nonrecurring | Commercial Real Estate Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	6,460	$ 493
Fair Value, Measurements, Nonrecurring | Agricultural Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	552
Fair Value, Measurements, Nonrecurring | Home Equity Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	366
Fair Value, Measurements, Nonrecurring | Residential Mortgage Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 24