Basis of Presentation (Non-Interest Income Including Revenue From Contracts With Customers In Scope Of ASU 2014-09) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Total non-interest income	$ 1,273	$ 1,306
Total Revenue Not Within the Scope of ASC 606 [Member]
Revenue from contracts with customers	154	211
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member]
Revenue from contracts with customers	1,119	1,095
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Service Charges [Member]
Revenue from contracts with customers	313	363
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Service Charges Non-sufficient Funds (NSF) Charges [Member]
Revenue from contracts with customers	159	188
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Service Charges Business Analysis Charges [Member]
Revenue from contracts with customers	41	42
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Service Charges Cycle Charges [Member
Revenue from contracts with customers	23	25
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Service Charges Lockbox Fees [Member]
Revenue from contracts with customers	44	47
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Service Charges Stop Payment Fees [Member]
Revenue from contracts with customers	4	5
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Service Charges Wire Transfer Fees [Member]
Revenue from contracts with customers	21	21
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Service Charges Other Service Charges [Member]
Revenue from contracts with customers	21	35
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Wealth Management [Member]
Revenue from contracts with customers	435	374
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Wealth Management DNB Investments & Insurance [Member]
Revenue from contracts with customers	89	102
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Wealth Management DNB First Investment Management & Trust [Member]
Revenue from contracts with customers	346	272
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Other Fee Income [Member]
Revenue from contracts with customers	371	358
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Other Fee Income Cardholder Interchange Fees [Member]
Revenue from contracts with customers	245	231
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Other Fee Income Safe Deposit Box [Member]
Revenue from contracts with customers	24	25
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Other Fee Income Check Printing [Member]
Revenue from contracts with customers	23	21
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Other Fee Income Merchant Card Processing [Member]
Revenue from contracts with customers	48	41
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Other Fee Income ATM Surcharges For Non-DNB Customers [Member]
Revenue from contracts with customers	17	18
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Other Fee Income Other Fee [Member]
Revenue from contracts with customers	$ 14	$ 22