Fair Values of Financial Instruments (Quantitative Information about Unobservable Inputs used in Recurring and Nonrecurring Level Three Fair Value Measurements) (Details) - Pooled Trust Preferred Securities - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 2,353	$ 2,355
Valuation Technique	Discounted cash flow	Discounted cash flow
Constant prepayment rate	2.00%	2.00%
Cumulative projected prepayments	40.00%	40.00%
Discount rate	6.80%	6.80%
Probability of default	1.70%	1.70%
Loss severity	21.40%	21.40%
Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Projected cures given deferral	0.00%	0.00%
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Projected cures given deferral	15.00%	15.00%