Fair Value Measurements, Quantitative Information About Unobservable Inputs Used In Recurring And Nonrecurring Level 3 Inputs (Details) - Nonrecurring [Member] - Level 3 [Member] - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Impaired Loans, Fair Value Calculated Using Estimated Sales Price [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value	$ 63	$ 1,753
Impaired loans [Member] | High [Member] | Discounted Cash Flows [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	8.25%	8.25%
Impaired loans [Member] | Low [Member] | Discounted Cash Flows [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	4.50%	3.25%
Impaired loans [Member] | Weighted Average [Member] | Discounted Cash Flows [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	6.88%	6.27%
Impaired Loans, Fair Value Calculated Using Disounted Cash Flows [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value	$ 947	$ 1,606