Loans Receivable and Allowance for Loan Losses, Classes of Loan Portfolio by Aging Categories of Performing and Nonaccrual Loans (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	$ 6,331,000		$ 6,331,000		$ 1,954,000
Current	683,381,000		683,381,000		666,197,000
Loans and Leases Receivable, Net Amount	689,712,000	$ 650,964,000	689,712,000	$ 650,964,000	668,151,000
Non-accrual	5,731,000		5,731,000		5,710,000
Interest which would have been recorded on the loans in nonaccrual status	238,000	200,000	713,000	1,200,000
Actual interest income recorded on nonaccrual loans	69,000	67,000	208,000	403,000
30 to 59 Days Past Due [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	1,663,000		1,663,000		1,954,000
60 to 89 Days Past Due [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	323,000		323,000
90+ Days Past Due [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	4,345,000		4,345,000
Residential Mortgage [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	3,844,000		3,844,000		1,006,000
Current	281,626,000		281,626,000		284,813,000
Loans and Leases Receivable, Net Amount	285,470,000	289,169,000	285,470,000	289,169,000	285,819,000
Non-accrual	3,784,000		3,784,000		3,891,000
Residential Mortgage [Member] | 30 to 59 Days Past Due [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	800,000		800,000		1,006,000
Residential Mortgage [Member] | 60 to 89 Days Past Due [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	143,000		143,000
Residential Mortgage [Member] | 90+ Days Past Due [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	2,901,000		2,901,000
Commercial [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Current	43,180,000		43,180,000		37,356,000
Loans and Leases Receivable, Net Amount	43,180,000	37,485,000	43,180,000	37,485,000	37,356,000
Non-accrual					78,000
Commercial Real Estate [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	724,000		724,000		948,000
Current	234,106,000		234,106,000		234,181,000
Loans and Leases Receivable, Net Amount	234,830,000	223,167,000	234,830,000	223,167,000	235,129,000
Non-accrual	476,000		476,000		159,000
Commercial Real Estate [Member] | 30 to 59 Days Past Due [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	452,000		452,000		948,000
Commercial Real Estate [Member] | 60 to 89 Days Past Due [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	113,000		113,000
Commercial Real Estate [Member] | 90+ Days Past Due [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	159,000		159,000
ADC [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	1,311,000		1,311,000
Current	111,683,000		111,683,000		93,060,000
Loans and Leases Receivable, Net Amount	112,994,000	84,164,000	112,994,000	84,164,000	93,060,000
Non-accrual	923,000		923,000		314,000
ADC [Member] | 30 to 59 Days Past Due [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	388,000		388,000
ADC [Member] | 60 to 89 Days Past Due [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	67,000		67,000
ADC [Member] | 90+ Days Past Due [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	856,000		856,000
Home Equity/2nds [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	452,000		452,000
Current	11,721,000		11,721,000		15,703,000
Loans and Leases Receivable, Net Amount	12,173,000	15,861,000	12,173,000	15,861,000	15,703,000
Non-accrual	548,000		548,000		1,268,000
Home Equity/2nds [Member] | 30 to 59 Days Past Due [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	23,000		23,000
Home Equity/2nds [Member] | 90+ Days Past Due [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	429,000		429,000
Consumer [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Current	1,065,000		1,065,000		1,084,000
Loans and Leases Receivable, Net Amount	$ 1,065,000	$ 1,118,000	$ 1,065,000	$ 1,118,000	$ 1,084,000