Loans Receivable and Allowance for Loan Losses, Changes in Allowance for Loan Losses and Recorded Investment (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Allowance for Loan losses [Roll Forward]
Beginning Balance	$ 8,169	$ 8,332	$ 8,055	$ 8,969
Charge-offs	(37)	(333)	(373)	(805)
Recoveries	125	94	575	204
Net (charge-offs) recoveries	88	(239)	202	(601)
Provision for (reversal of) loan losses		(375)		(650)
Ending Balance	8,257	7,718	8,257	7,718
Ending balance - individually evaluated for impairment					$ 2,453	$ 1,413	$ 1,767
Ending balance - collectively evaluated for impairment					5,804	6,642	5,951
Ending balance	8,169	8,332	8,055	8,969	8,257	8,055	7,718
Ending loan balance - individually evaluated for impairment					22,816	22,211	22,894
Ending loan balance - collectively evaluated for impairment					664,096	645,940	608,550
Ending loan balance					686,912	668,151	631,444
Residential Mortgage [Member]
Allowance for Loan losses [Roll Forward]
Beginning Balance	3,301	3,789	3,099	3,833
Charge-offs	(37)	(208)	(360)	(707)
Recoveries	1	32	222	139
Net (charge-offs) recoveries	(36)	(176)	(138)	(568)
Provision for (reversal of) loan losses	(303)	(210)	1	138
Ending Balance	2,962	3,403	2,962	3,403
Ending balance - individually evaluated for impairment					1,295	1,181	1,524
Ending balance - collectively evaluated for impairment					1,667	1,918	1,879
Ending balance	3,301	3,789	3,099	3,833	2,962	3,099	3,403
Ending loan balance - individually evaluated for impairment					15,926	18,219	15,919
Ending loan balance - collectively evaluated for impairment					273,503	267,600	269,988
Ending loan balance					289,429	285,819	285,907
Commercial [Member]
Allowance for Loan losses [Roll Forward]
Beginning Balance	514	473	527	478
Charge-offs		(27)
Net (charge-offs) recoveries		(27)
Provision for (reversal of) loan losses	(100)	(57)	(113)	(89)
Ending Balance	414	389	414	389
Ending balance - collectively evaluated for impairment					414	527	389
Ending balance	514	473	527	478	414	527	389
Ending loan balance - individually evaluated for impairment					300
Ending loan balance - collectively evaluated for impairment					42,318	37,356	25,811
Ending loan balance					42,618	37,356	25,811
Commercial Real Estate [Member]
Allowance for Loan losses [Roll Forward]
Beginning Balance	2,995	2,515	2,805	2,535
Recoveries	122	60	333	60
Net (charge-offs) recoveries	122	60	333	60
Provision for (reversal of) loan losses	(526)	(4)	(547)	(24)
Ending Balance	2,591	2,571	2,591	2,571
Ending balance - individually evaluated for impairment					153	182	189
Ending balance - collectively evaluated for impairment					2,438	2,623	2,382
Ending balance	2,995	2,515	2,805	2,535	2,591	2,805	2,571
Ending loan balance - individually evaluated for impairment					2,003	2,917	6,078
Ending loan balance - collectively evaluated for impairment					230,835	232,212	210,310
Ending loan balance					232,838	235,129	216,388
ADC [Member]
Allowance for Loan losses [Roll Forward]
Beginning Balance	1,060	1,097	1,236	1,390
Charge-offs			(13)
Net (charge-offs) recoveries			(13)
Provision for (reversal of) loan losses	1,000	(113)	837	(406)
Ending Balance	2,060	984	2,060	984
Ending balance - individually evaluated for impairment					1,002	48	51
Ending balance - collectively evaluated for impairment					1,058	1,188	933
Ending balance	1,060	1,097	1,236	1,390	2,060	1,236	984
Ending loan balance - individually evaluated for impairment					3,046	991	807
Ending loan balance - collectively evaluated for impairment					104,518	92,069	85,091
Ending loan balance					107,564	93,060	85,898
Home Equity/2nds [Member]
Allowance for Loan losses [Roll Forward]
Beginning Balance	297	453	386	728
Charge-offs		(98)		(98)
Recoveries	2	2	20	5
Net (charge-offs) recoveries	2	(96)	20	(93)
Provision for (reversal of) loan losses	(70)	10	(177)	(268)
Ending Balance	229	367	229	367
Ending balance - individually evaluated for impairment					2
Ending balance - collectively evaluated for impairment					227	386	367
Ending balance	297	453	386	728	229	386	367
Ending loan balance - individually evaluated for impairment					1,461
Ending loan balance - collectively evaluated for impairment					11,976	15,703	16,336
Ending loan balance					13,437	15,703	16,336
Consumer [Member]
Allowance for Loan losses [Roll Forward]
Beginning Balance	2	5	2	5
Provision for (reversal of) loan losses	(1)	(1)	(1)	(1)
Ending Balance	1	4	1	4
Ending balance - individually evaluated for impairment					1	2	3
Ending balance - collectively evaluated for impairment							1
Ending balance	$ 2	$ 5	$ 2	$ 5	1	2	4
Ending loan balance - individually evaluated for impairment					80	84	90
Ending loan balance - collectively evaluated for impairment					946	1,000	1,014
Ending loan balance					$ 1,026	$ 1,084	$ 1,104

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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Amount, after recoveries, of loans and leases that have been written-off.

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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The balance of financing receivables that were collectively evaluated for impairment.

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The balance of financing receivables that were individually evaluated for impairment.

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- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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Amount of expense related to estimated loss from loan and lease transactions.

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