Fair Value Measurements (Nonrecurring Basis Significant Unobservable Inputs) (Details) - Fair Value, Measurements, Nonrecurring - Level 3 $ in Millions	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 22.3	$ 9.7
OREO
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 0.1	$ 0.4
Measurement Input, Discount Rate | Lower Limit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, Range of Discounts Applied	0.150	0.150
OREO, Range of Discounts Applied	0.150	0.150
Measurement Input, Discount Rate | Upper Limit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans, Range of Discounts Applied	0.300	0.300
OREO, Range of Discounts Applied	0.300	0.300
Loans | Measurement Input, Discount Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 22.3	$ 24.9
OREO
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 0.1	$ 0.4