Fair Value Measurements (Quantitative Information About Level 3 Fair Value Measurements For Certain Financial Assets) (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Impaired Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Quantitative information about level 3 nonrecurring basis	9.00%	8.00%
Fair Value Inputs, Discount Rate	5.00%	5.00%
Other Real Estate Owned [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Quantitative information about level 3 nonrecurring basis	6.00%	6.00%
Nonrecurring [Member] | Maximum [Member] | Impaired Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Quantitative information about level 3 nonrecurring basis	12.00%	12.00%
Fair Value Inputs, Discount Rate	6.00%	6.00%
Nonrecurring [Member] | Maximum [Member] | Other Real Estate Owned [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Quantitative information about level 3 nonrecurring basis	6.00%	6.00%
Nonrecurring [Member] | Minimum [Member] | Impaired Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Quantitative information about level 3 nonrecurring basis	0.00%	0.00%
Fair Value Inputs, Discount Rate	4.00%	4.00%
Nonrecurring [Member] | Minimum [Member] | Other Real Estate Owned [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Quantitative information about level 3 nonrecurring basis	6.00%	6.00%