Fair Value (Quantitative Information of Fair Value Measurements) (Details) - Impaired Loans - Significant Unobservable Inputs (Level 3) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Commercial and Industrial Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 2,622	$ 60
Commercial and Industrial Loans | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	21.00%	0.00%
Commercial and Industrial Loans | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	95.00%	100.00%
Commercial and Industrial Loans | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	29.00%	89.00%
Commercial Real Estate Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 1,966	$ 348
Commercial Real Estate Loans | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	28.00%	33.00%
Commercial Real Estate Loans | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	76.00%	77.00%
Commercial Real Estate Loans | Weighted Average
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	49.00%	56.00%
Agricultural Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 158
Range (Weighted Average)	34.00%
Agricultural Loans | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	34.00%