Loans Receivable and Allowance for Loan Losses, Classes of Loan Portfolio by Aging Categories of Performing and Nonaccrual Loans (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	$ 4,353,000		$ 5,260,000
Current	669,867,000		677,089,000
Loans receivable	674,220,000	$ 669,912,000	682,349,000
Non-accrual	3,795,000		4,656,000
Interest which would have been recorded on the loans in nonaccrual status	412,000	462,000,000,000
Actual interest income recorded on nonaccrual loans	22,000	34,000
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	1,446,000		1,561,000
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	12,000
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	2,895,000		3,699,000
Residential Mortgage [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	2,572,000		2,854,000
Current	266,871,000		271,905,000
Loans receivable	269,443,000	285,023,000	274,759,000
Non-accrual	2,170,000		2,580,000
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	833,000		1,060,000
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	1,739,000		1,794,000
Commercial [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due			430,000
Current	44,725,000		35,454,000
Loans receivable	44,725,000	39,015,000	35,884,000
Non-accrual			430,000
Commercial [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			430,000
Commercial Real Estate [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	1,063,000		797,000
Current	236,196,000		241,896,000
Loans receivable	237,259,000	230,336,000	242,693,000
Non-accrual	814,000		660,000
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		137,000
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	611,000		660,000
ADC [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	470,000		642,000
Current	108,463,000		113,898,000
Loans receivable	108,933,000	100,635,000	114,540,000
Non-accrual	388,000		558,000
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	82,000		255,000
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	388,000		387,000
Home Equity/2nds [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	233,000		524,000
Current	12,481,000		12,862,000
Loans receivable	12,714,000	13,853,000	13,386,000
Non-accrual	423,000		428,000
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	76,000		96,000
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	157,000		428,000
Consumer [Member]
Classes of the loan portfolio summarized by the aging categories of performing loans and nonaccrual loans [Abstract]
Total past due	15,000		13,000
Current	1,131,000		1,074,000
Loans receivable	1,146,000	$ 1,050,000	1,087,000
Consumer [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	3,000		$ 13,000
Consumer [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	$ 12,000