Allowance for Credit Losses (Allowance For Credit Losses And Recorded Investments In Loans Receivables) (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]          
Beginning balance $ 5,267 $ 5,247 $ 5,373 $ 4,935 $ 4,935
Charge-offs (50) (47) (1,139) (277)  
Recoveries 2 3 75 15  
Provisions 375 100 1,285 630  
Ending balance 5,594 5,303 5,594 5,303 5,373
Ending balance: individually evaluated for impairment 95   95   334
Ending balance: collectively evaluated for impairment 5,499   5,499   5,039
Ending balance: Loans receivables 819,753   819,753   817,529
Ending Balance: individually evaluated for impairment 7,624   7,624   6,919
Ending Balance: collectively evaluated for impairment 810,977   810,977   808,925
Reserve for unfunded loan commitments included in other liabilities     309 199 345
Receivables Acquired with Deteriorated Credit Quality [Member]          
Financing Receivable, Allowance for Credit Losses [Line Items]          
Ending balance: Loans receivables 1,152   1,152   1,685
Residential Mortgage [Member]          
Financing Receivable, Allowance for Credit Losses [Line Items]          
Beginning balance 245 314 349 216 216
Charge-offs     (206)  
Recoveries   2 2 10  
Provisions 1 87 (105) 383  
Ending balance 246 403 246 403 349
Ending balance: individually evaluated for impairment 45   45   143
Ending balance: collectively evaluated for impairment 201   201   206
Ending balance: Loans receivables 88,249   88,249   87,581
Ending Balance: individually evaluated for impairment 2,059   2,059   1,760
Ending Balance: collectively evaluated for impairment 86,179   86,179   85,810
Residential Mortgage [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]          
Financing Receivable, Allowance for Credit Losses [Line Items]          
Ending balance: Loans receivables 11   11   11
Commercial Mortgage [Member]          
Financing Receivable, Allowance for Credit Losses [Line Items]          
Beginning balance 2,634 2,370 2,531 2,375 2,375
Charge-offs (36) (39) (519) (39)  
Recoveries     50    
Provisions 200 141 736 136  
Ending balance 2,798 2,472 2,798 2,472 2,531
Ending balance: individually evaluated for impairment 22   22    
Ending balance: collectively evaluated for impairment 2,776   2,776   2,531
Ending balance: Loans receivables 461,012   461,012   465,486
Ending Balance: individually evaluated for impairment 2,688   2,688   2,919
Ending Balance: collectively evaluated for impairment 457,183   457,183   460,893
Reserve for unfunded loan commitments included in other liabilities     3 3 4
Commercial Mortgage [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]          
Financing Receivable, Allowance for Credit Losses [Line Items]          
Ending balance: Loans receivables 1,141   1,141   1,674
Commercial Term [Member]          
Financing Receivable, Allowance for Credit Losses [Line Items]          
Beginning balance 625 891 709 989 989
Charge-offs (14) (8) (610) (32)  
Recoveries 1   20 1  
Provisions 36 (90) 529 (165)  
Ending balance 648 793 648 793 709
Ending balance: individually evaluated for impairment         97
Ending balance: collectively evaluated for impairment 648   648   612
Ending balance: Loans receivables 120,786   120,786   123,175
Ending Balance: individually evaluated for impairment 1,506   1,506   198
Ending Balance: collectively evaluated for impairment 119,280   119,280   122,977
Reserve for unfunded loan commitments included in other liabilities     150 119 135
Commercial Construction [Member]          
Financing Receivable, Allowance for Credit Losses [Line Items]          
Beginning balance 1,208 866 969 569 569
Charge-offs        
Recoveries       1  
Provisions (102) 7 137 303  
Ending balance 1,106 873 1,106 873 969
Ending balance: individually evaluated for impairment         89
Ending balance: collectively evaluated for impairment 1,106   1,106   880
Ending balance: Loans receivables 84,428   84,428   72,755
Ending Balance: individually evaluated for impairment 447   447   1,242
Ending Balance: collectively evaluated for impairment 83,981   83,981   71,513
Reserve for unfunded loan commitments included in other liabilities     139 64 190
Leases Financing [Member]          
Financing Receivable, Allowance for Credit Losses [Line Items]          
Charge-offs        
Recoveries   1 1 2  
Provisions   (1) (1) (2)  
Consumer: Home Equity [Member]          
Financing Receivable, Allowance for Credit Losses [Line Items]          
Beginning balance 189 191 196 195 195
Charge-offs        
Provisions (3) 11 (10) 7  
Ending balance 186 202 186 202 196
Ending balance: collectively evaluated for impairment 186   186   196
Ending balance: Loans receivables 59,433   59,433   62,560
Ending Balance: individually evaluated for impairment 616   616   544
Ending Balance: collectively evaluated for impairment 58,817   58,817   62,016
Reserve for unfunded loan commitments included in other liabilities     17 13 16
Consumer: Other [Member]          
Financing Receivable, Allowance for Credit Losses [Line Items]          
Beginning balance 84 64 61 64 64
Charge-offs     (10)    
Recoveries 1   2 1  
Provisions (4) (2) 28 (3)  
Ending balance 81 62 81 62 61
Ending balance: individually evaluated for impairment 28   28   5
Ending balance: collectively evaluated for impairment 53   53   56
Ending balance: Loans receivables 5,845   5,845   5,972
Ending Balance: individually evaluated for impairment 308   308   256
Ending Balance: collectively evaluated for impairment 5,537   5,537   5,716
Unallocated [Member]          
Financing Receivable, Allowance for Credit Losses [Line Items]          
Beginning balance 282 551 558 527 527
Charge-offs        
Provisions 247 (53) (29) (29)  
Ending balance 529 $ 498 529 $ 498 558
Ending balance: collectively evaluated for impairment $ 529   $ 529   $ 558