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		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Total non-interest income	$ 1,332	$ 1,422	$ 2,605	$ 2,728
Total Revenue Not Within the Scope of ASC 606 [Member]
Revenue from contracts with customers	177	247	331	458
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member]
Revenue from contracts with customers	1,155	1,175	2,274	2,270
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Service Charges [Member]
Revenue from contracts with customers	261	291	574	654
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Service Charges Non-Sufficient Funds Charges [Member]
Revenue from contracts with customers	142	177	301	365
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Service Charges Business Analysis Charges [Member]
Revenue from contracts with customers	44	39	85	81
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Service Charges Cycle Charges [Member
Revenue from contracts with customers	22	21	45	46
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Service Charges Lockbox Fees [Member]
Revenue from contracts with customers	8	8	52	55
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Service Charges Stop Payment Fees [Member]
Revenue from contracts with customers	3	5	7	10
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Service Charges Wire Transfer Fees [Member]
Revenue from contracts with customers	22	23	43	44
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Service Charges Other Service Charges [Member]
Revenue from contracts with customers	20	18	41	53
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Wealth Management [Member]
Revenue from contracts with customers	512	471	947	845
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Wealth Management DNB Investments & Insurance [Member]
Revenue from contracts with customers	150	144	238	246
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	362	327	709	599
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Other Fee Income [Member]
Revenue from contracts with customers	382	413	753	771
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Other Fee Income Cardholder Interchange Fees [Member]
Revenue from contracts with customers	269	257	514	488
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Other Fee Income Safe Deposit Box [Member]
Revenue from contracts with customers	26	25	50	50
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Other Fee Income Check Printing [Member]
Revenue from contracts with customers	12	18	35	39
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Other Fee Income Merchant Card Processing [Member]
Revenue from contracts with customers	42	56	90	97
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	20	22	37	40
Revenue from Contracts with Customers in Scope of ASU 2014-09 [Member] | Other Fee Income Other Fee [Member]
Revenue from contracts with customers	$ 13	$ 35	$ 27	$ 57