Loans (Information on Non-Accrual Loans) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	$ 6,721	$ 6,862	$ 6,721	$ 6,862	$ 7,499
Loans 90 day past due and accruing	23		23		54
Total non-performing loans	6,744	6,862	6,744	6,862	7,553
Interest income that would have been recorded under original terms, non-accrual loans	107	144	230	300
Interest income that would have been recorded under original terms, 90 days past due and accruing	1		1
Interest income that would have been recorded under original terms	108	144	231	300
Interest income recorded during the period, 90 days past due and accruing	1		1
Interest income recorded during the period	1		1
Net impact on interest income, non-accrual loans	107	144	230	300
Net impact on interest income	107	144	230	300
Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	1,344	1,815	1,344	1,815	1,915
Interest income that would have been recorded under original terms, non-accrual loans	18	21	43	42
Net impact on interest income, non-accrual loans	18	21	43	42
Commercial Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	1,593	2,375	1,593	2,375	2,259
Interest income that would have been recorded under original terms, non-accrual loans	28	36	58	77
Net impact on interest income, non-accrual loans	28	36	58	77
Commercial Term [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	2,583	1,510	2,583	1,510	2,100
Loans 90 day past due and accruing	23		23
Interest income that would have been recorded under original terms, non-accrual loans	46	28	90	66
Net impact on interest income, non-accrual loans	46	28	90	66
Commercial Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	488	447	488	447	514
Interest income that would have been recorded under original terms, non-accrual loans	9	46	20	91
Net impact on interest income, non-accrual loans	9	46	20	91
Consumer: Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	498	404	498	404	466
Interest income that would have been recorded under original terms, non-accrual loans	3	6	8	12
Net impact on interest income, non-accrual loans	3	6	8	12
Consumer: Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non-accrual loans	215	311	215	311	245
Loans 90 day past due and accruing					$ 54
Interest income that would have been recorded under original terms, non-accrual loans	3	7	11	12
Net impact on interest income, non-accrual loans	$ 3	$ 7	$ 11	$ 12