Fair Value (Fair Value Assets and Liabilities Measured on Nonrecurring Basis Validation Techniques) (Details) - Significant Unobservable Inputs (Level 3) - Impaired Loans - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Commercial and Industrial Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 3,354	$ 60
Commercial and Industrial Loans | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	0.00%	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)	84.00%	89.00%
Commercial Real Estate Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 3,438	$ 348
Commercial Real Estate Loans | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range (Weighted Average)	30.00%	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)	47.00%	56.00%