Loans (Composition of Total Loans Outstanding) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 933,697	$ 934,971
Less allowance for credit losses	(6,719)	(6,675)	$ (6,145)	$ (5,843)
Net loans	926,978	928,296
Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	101,039	99,932
Less allowance for credit losses	(156)	(161)	(226)	(221)
Commercial Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	517,236	535,735
Less allowance for credit losses	(3,493)	(3,647)	(2,987)	(2,856)
Commercial Term [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	182,077	166,335
Less allowance for credit losses	(1,189)	(1,062)	(904)	(845)
Commercial Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	78,967	76,302
Less allowance for credit losses	(1,080)	(1,032)	(1,219)	(1,128)
Consumer: Home Equity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	49,412	51,536
Less allowance for credit losses	(183)	(190)	(176)	(183)
Consumer: Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	4,966	5,131
Less allowance for credit losses	$ (43)	$ (46)	$ (55)	$ (63)