Loans (Details) $ in Thousands	12 Months Ended
Dec. 31, 2015 USD ($) loan	Dec. 31, 2014 USD ($) loan	Dec. 31, 2013 USD ($)
Composition of Loan Portfolio [Abstract]
Amount of loan portfolio	$ 988,638	$ 917,564	$ 876,367
Percentage of loan portfolio (in hundredths)	100.00%	100.00%
Loans Receivable to Related Party [Roll Forward]
Balance at beginning of year	$ 14,856	$ 14,884
New loans	7,382	8,932
Repayments	(1,837)	(8,960)
Balance at end of year	20,401	14,856	14,884
Loans, aging disclosure [Abstract]
All Past Due	8,287	11,863
Current	980,351	905,701
Amount of loan portfolio	988,638	917,564	876,367
90 Plus Days And Accruing	136	181
Nonaccrual Loans [Abstract]
Nonaccrual loans	7,372	10,510
Average investment in impaired loans	32,698	38,404	45,722
Interest income recognized on impaired loans, all on cash basis	1,218	1,465	1,750
Balance of impaired loans	29,531	35,862	42,351
Less portion for which no allowance for loan losses is allocated	(20,889)	(26,313)
Portion of impaired loan balance for which an allowance for loan losses is allocated	8,642	9,549
Portion of allowance for loan losses allocated to the impaired loan balance	754	1,803	2,461
Recorded Investment	29,531	35,862	42,351
Unpaid Principal Balance	31,906	39,026	46,408
Average Recorded Investment	32,698	38,404	45,722
Recognized Interest Income	$ 1,218	$ 1,465	1,750
Troubled Debt Restructured, Number of Loans \| loan	84	94
Troubled Debt Restructured, Balance	$ 23,923	$ 27,214
Troubled Debt Restructured, Specific Reserves	$ 455	$ 868
Troubled Debt Restructured (Greater than 30 days), Number of Loans \| loan	8	12
Financing Receivable Recorded Investment Greater Than30 Days Past Due	$ 1,053	$ 1,549
Troubled Debt Restructured (Greater than 30 days), Balance	1,053	1,549
Troubled Debt Restructured (Greater than 30 days), Specific Reserves	$ 46	$ 177
Financing Receivable, Number of Loans \| loan	2	6
Financing Receivable Modifications Pre Modification Recorded Investment During Period	$ 218	$ 826
Financing Receivable, Pre-Modification Outstanding Recorded Investment	221	929
Financing Receivable, Post-Modification Outstanding Recorded Investment	218	826
Financing Receivable, Specific Reserves	0	12
Net deferred loan costs included in loan balances	3,686	2,729
Loans used to collateralize borrowings from the Federal Home Loan Bank of Boston	279,463	266,716
Commercial, construction and home equity loans used to collateralize unused line of credit at the Federal Reserve Bank of Boston	243,578	240,943
Interest income which would have been recognized on these loans, if interest had been accrued	369	551	917
Loans to directors, officers and employees	$ 31,285	$ 29,883
Financing Receivable, Modifications, Subsequent Default, Number of Contracts \| loan	0	2
Financing Receivable, Loans Classified as Troubled Debt Restructurings That Had Been Placed on TDR Status in Previous 12 Months		$ 238
Loans classified as TDRs that are involved in bankruptcy	$ 1,079
Number of loans classified as TDRs that were on non-accrual status \| loan	13
Loans classified as TDRs that were on non-accrual status	$ 1,764
Number of loans classified as TDRs that are involved in foreclosure \| loan	3
Loans classified as TDRs that are involved in foreclosure	$ 262
Number of mortgage loans in the process of foreclosure \| loan	16
Mortgage loans in the process of foreclosure	$ 1,513
Loans Receivable in Bankruptcy
Nonaccrual Loans [Abstract]
Financing Receivable, Number of Loans \| loan	6
30-59 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	$ 2,122	2,142
60-89 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	2,379	1,356
90 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	3,786	8,365
With No Related Allowance Recorded
Nonaccrual Loans [Abstract]
Average investment in impaired loans	22,808	26,926	31,541
Balance of impaired loans	20,889	26,313	32,417
Portion of allowance for loan losses allocated to the impaired loan balance	0	0	0
Recorded Investment	20,889	26,313	32,417
Unpaid Principal Balance	22,947	29,077	36,119
Average Recorded Investment	22,808	26,926	31,541
Recognized Interest Income	839	1,078	1,360
With an Allowance Recorded
Nonaccrual Loans [Abstract]
Average investment in impaired loans	9,890	11,478	14,181
Balance of impaired loans	8,642	9,549	9,934
Portion of allowance for loan losses allocated to the impaired loan balance	754	1,803	2,461
Recorded Investment	8,642	9,549	9,934
Unpaid Principal Balance	8,959	9,949	10,289
Average Recorded Investment	9,890	11,478	14,181
Recognized Interest Income	381	387	390
Commercial Real Estate
Composition of Loan Portfolio [Abstract]
Amount of loan portfolio	$ 269,462	$ 242,311
Percentage of loan portfolio (in hundredths)	27.30%	26.40%
Loans, aging disclosure [Abstract]
All Past Due	$ 884	$ 860
Current	268,578	241,451
Amount of loan portfolio	269,462	242,311
90 Plus Days And Accruing	0	0
Nonaccrual Loans [Abstract]
Nonaccrual loans	915	2,088
Average investment in impaired loans	12,056	14,120	16,773
Balance of impaired loans	10,717	13,304	14,935
Portion of allowance for loan losses allocated to the impaired loan balance	89	346	890
Recorded Investment	10,717	13,304	14,935
Unpaid Principal Balance	11,123	14,212	15,683
Average Recorded Investment	12,056	14,120	16,773
Recognized Interest Income	$ 450	$ 550	645
Troubled Debt Restructured, Number of Loans \| loan	15	19
Troubled Debt Restructured, Balance	$ 10,350	$ 12,282
Troubled Debt Restructured, Specific Reserves	$ 85	$ 267
Troubled Debt Restructured (Greater than 30 days), Number of Loans \| loan	0	1
Troubled Debt Restructured (Greater than 30 days), Balance	$ 0	$ 321
Troubled Debt Restructured (Greater than 30 days), Specific Reserves	$ 0	$ 120
Financing Receivable, Number of Loans \| loan	0	2
Financing Receivable, Pre-Modification Outstanding Recorded Investment	$ 0	$ 302
Financing Receivable, Post-Modification Outstanding Recorded Investment	0	300
Financing Receivable, Specific Reserves	0	0
Commercial Real Estate \| 30-59 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	603	24
Commercial Real Estate \| 60-89 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	0	75
Commercial Real Estate \| 90 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	281	761
Commercial Real Estate \| With No Related Allowance Recorded
Nonaccrual Loans [Abstract]
Average investment in impaired loans	8,990	11,080	11,100
Balance of impaired loans	7,173	11,687	11,813
Portion of allowance for loan losses allocated to the impaired loan balance	0	0	0
Recorded Investment	7,173	11,687	11,813
Unpaid Principal Balance	7,496	12,423	12,419
Average Recorded Investment	8,990	11,080	11,100
Recognized Interest Income	301	488	495
Commercial Real Estate \| With an Allowance Recorded
Nonaccrual Loans [Abstract]
Average investment in impaired loans	3,066	3,040	5,673
Balance of impaired loans	3,544	1,617	3,122
Portion of allowance for loan losses allocated to the impaired loan balance	89	346	890
Recorded Investment	3,544	1,617	3,122
Unpaid Principal Balance	3,627	1,789	3,264
Average Recorded Investment	3,066	3,040	5,673
Recognized Interest Income	149	62	150
Commercial Construction
Composition of Loan Portfolio [Abstract]
Amount of loan portfolio	$ 24,881	$ 30,932
Percentage of loan portfolio (in hundredths)	2.50%	3.40%
Loans, aging disclosure [Abstract]
All Past Due	$ 273	$ 249
Current	24,608	30,683
Amount of loan portfolio	24,881	30,932
90 Plus Days And Accruing	0	0
Nonaccrual Loans [Abstract]
Nonaccrual loans	238	208
Average investment in impaired loans	1,156	1,309	1,997
Balance of impaired loans	1,026	1,380	1,284
Portion of allowance for loan losses allocated to the impaired loan balance	302	413	272
Recorded Investment	1,026	1,380	1,284
Unpaid Principal Balance	1,026	1,380	1,284
Average Recorded Investment	1,156	1,309	1,997
Recognized Interest Income	$ 45	$ 56	48
Troubled Debt Restructured, Number of Loans \| loan	1	1
Troubled Debt Restructured, Balance	$ 788	$ 1,172
Troubled Debt Restructured, Specific Reserves	$ 94	$ 207
Troubled Debt Restructured (Greater than 30 days), Number of Loans \| loan	0	0
Troubled Debt Restructured (Greater than 30 days), Balance	$ 0	$ 0
Troubled Debt Restructured (Greater than 30 days), Specific Reserves	$ 0	$ 0
Financing Receivable, Number of Loans \| loan	0	0
Financing Receivable, Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Financing Receivable, Post-Modification Outstanding Recorded Investment	0	0
Financing Receivable, Specific Reserves	0	0
Commercial Construction \| 30-59 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	35	0
Commercial Construction \| 60-89 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	0	41
Commercial Construction \| 90 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	238	208
Commercial Construction \| With No Related Allowance Recorded
Nonaccrual Loans [Abstract]
Average investment in impaired loans	3	30	202
Balance of impaired loans	30	0	0
Portion of allowance for loan losses allocated to the impaired loan balance	0	0	0
Recorded Investment	30	0	0
Unpaid Principal Balance	30	0	0
Average Recorded Investment	3	30	202
Recognized Interest Income	1	0	0
Commercial Construction \| With an Allowance Recorded
Nonaccrual Loans [Abstract]
Average investment in impaired loans	1,153	1,279	1,795
Balance of impaired loans	996	1,380	1,284
Portion of allowance for loan losses allocated to the impaired loan balance	302	413	272
Recorded Investment	996	1,380	1,284
Unpaid Principal Balance	996	1,380	1,284
Average Recorded Investment	1,153	1,279	1,795
Recognized Interest Income	44	56	48
Commercial Other
Composition of Loan Portfolio [Abstract]
Amount of loan portfolio	$ 128,341	$ 104,531	95,289
Percentage of loan portfolio (in hundredths)	13.00%	11.40%
Loans, aging disclosure [Abstract]
All Past Due	$ 328	$ 860
Current	128,013	103,671
Amount of loan portfolio	128,341	104,531	95,289
90 Plus Days And Accruing	25	0
Nonaccrual Loans [Abstract]
Nonaccrual loans	66	935
Average investment in impaired loans	2,149	4,956	5,898
Balance of impaired loans	1,234	2,942	6,698
Portion of allowance for loan losses allocated to the impaired loan balance	8	129	841
Recorded Investment	1,234	2,942	6,698
Unpaid Principal Balance	1,287	3,745	8,441
Average Recorded Investment	2,149	4,956	5,898
Recognized Interest Income	$ 80	$ 169	350
Troubled Debt Restructured, Number of Loans \| loan	11	15
Troubled Debt Restructured, Balance	$ 1,168	$ 2,007
Troubled Debt Restructured, Specific Reserves	$ 1	$ 0
Troubled Debt Restructured (Greater than 30 days), Number of Loans \| loan	0	1
Troubled Debt Restructured (Greater than 30 days), Balance	$ 0	$ 2
Troubled Debt Restructured (Greater than 30 days), Specific Reserves	$ 0	$ 0
Financing Receivable, Number of Loans \| loan	0	0
Financing Receivable, Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Financing Receivable, Post-Modification Outstanding Recorded Investment	0	0
Financing Receivable, Specific Reserves	0	0
Commercial Other \| 30-59 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	303	3
Commercial Other \| 60-89 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	0	0
Commercial Other \| 90 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	25	857
Commercial Other \| With No Related Allowance Recorded
Nonaccrual Loans [Abstract]
Average investment in impaired loans	1,893	3,853	4,265
Balance of impaired loans	1,163	2,616	5,617
Portion of allowance for loan losses allocated to the impaired loan balance	0	0	0
Recorded Investment	1,163	2,616	5,617
Unpaid Principal Balance	1,210	3,407	7,309
Average Recorded Investment	1,893	3,853	4,265
Recognized Interest Income	76	156	322
Commercial Other \| With an Allowance Recorded
Nonaccrual Loans [Abstract]
Average investment in impaired loans	256	1,103	1,633
Balance of impaired loans	71	326	1,081
Portion of allowance for loan losses allocated to the impaired loan balance	8	129	841
Recorded Investment	71	326	1,081
Unpaid Principal Balance	77	338	1,132
Average Recorded Investment	256	1,103	1,633
Recognized Interest Income	5	13	28
Municipal
Composition of Loan Portfolio [Abstract]
Amount of loan portfolio	$ 19,751	$ 20,424	19,117
Percentage of loan portfolio (in hundredths)	2.00%	2.20%
Loans, aging disclosure [Abstract]
All Past Due	$ 0	$ 0
Current	19,751	20,424
Amount of loan portfolio	19,751	20,424	19,117
90 Plus Days And Accruing	0	0
Nonaccrual Loans [Abstract]
Nonaccrual loans	0	0
Average investment in impaired loans	0	0	0
Balance of impaired loans	0	0	0
Portion of allowance for loan losses allocated to the impaired loan balance	0	0	0
Recorded Investment	0	0	0
Unpaid Principal Balance	0	0	0
Average Recorded Investment	0	0	0
Recognized Interest Income	$ 0	$ 0	0
Troubled Debt Restructured, Number of Loans \| loan	0	0
Troubled Debt Restructured, Balance	$ 0	$ 0
Troubled Debt Restructured, Specific Reserves	$ 0	$ 0
Troubled Debt Restructured (Greater than 30 days), Number of Loans \| loan	0	0
Troubled Debt Restructured (Greater than 30 days), Balance	$ 0	$ 0
Troubled Debt Restructured (Greater than 30 days), Specific Reserves	$ 0	$ 0
Financing Receivable, Number of Loans \| loan	0	0
Financing Receivable, Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Financing Receivable, Post-Modification Outstanding Recorded Investment	0	0
Financing Receivable, Specific Reserves	0	0
Municipal \| 30-59 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	0	0
Municipal \| 60-89 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	0	0
Municipal \| 90 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	0	0
Municipal \| With No Related Allowance Recorded
Nonaccrual Loans [Abstract]
Average investment in impaired loans	0	0	0
Balance of impaired loans	0	0	0
Portion of allowance for loan losses allocated to the impaired loan balance	0	0	0
Recorded Investment	0	0	0
Unpaid Principal Balance	0	0	0
Average Recorded Investment	0	0	0
Recognized Interest Income	0	0	0
Municipal \| With an Allowance Recorded
Nonaccrual Loans [Abstract]
Average investment in impaired loans	0	0	0
Balance of impaired loans	0	0	0
Portion of allowance for loan losses allocated to the impaired loan balance	0	0	0
Recorded Investment	0	0	0
Unpaid Principal Balance	0	0	0
Average Recorded Investment	0	0	0
Recognized Interest Income	0	0	0
Residential Term
Composition of Loan Portfolio [Abstract]
Amount of loan portfolio	$ 403,030	$ 384,032	377,218
Percentage of loan portfolio (in hundredths)	40.70%	41.90%
Loans, aging disclosure [Abstract]
All Past Due	$ 5,187	$ 7,003
Current	397,843	377,029
Amount of loan portfolio	403,030	384,032	377,218
90 Plus Days And Accruing	100	101
Nonaccrual Loans [Abstract]
Nonaccrual loans	5,260	6,421
Average investment in impaired loans	15,708	16,243	19,378
Balance of impaired loans	15,088	16,123	17,786
Portion of allowance for loan losses allocated to the impaired loan balance	326	519	404
Recorded Investment	15,088	16,123	17,786
Unpaid Principal Balance	16,350	17,337	19,116
Average Recorded Investment	15,708	16,243	19,378
Recognized Interest Income	$ 595	$ 641	673
Troubled Debt Restructured, Number of Loans \| loan	53	54
Troubled Debt Restructured, Balance	$ 10,875	$ 10,932
Troubled Debt Restructured, Specific Reserves	$ 275	$ 373
Troubled Debt Restructured (Greater than 30 days), Number of Loans \| loan	8	8
Troubled Debt Restructured (Greater than 30 days), Balance	$ 1,053	$ 1,000
Troubled Debt Restructured (Greater than 30 days), Specific Reserves	$ 46	$ 36
Financing Receivable, Number of Loans \| loan	2	4
Financing Receivable, Pre-Modification Outstanding Recorded Investment	$ 221	$ 627
Financing Receivable, Post-Modification Outstanding Recorded Investment	218	526
Financing Receivable, Specific Reserves	0	12
Residential Term \| 30-59 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	450	856
Residential Term \| 60-89 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	2,098	468
Residential Term \| 90 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	2,639	5,679
Residential Term \| With No Related Allowance Recorded
Nonaccrual Loans [Abstract]
Average investment in impaired loans	10,480	10,505	14,396
Balance of impaired loans	11,122	10,820	13,432
Portion of allowance for loan losses allocated to the impaired loan balance	0	0	0
Recorded Investment	11,122	10,820	13,432
Unpaid Principal Balance	12,157	11,824	14,600
Average Recorded Investment	10,480	10,505	14,396
Recognized Interest Income	415	402	511
Residential Term \| With an Allowance Recorded
Nonaccrual Loans [Abstract]
Average investment in impaired loans	5,228	5,738	4,982
Balance of impaired loans	3,966	5,303	4,354
Portion of allowance for loan losses allocated to the impaired loan balance	326	519	404
Recorded Investment	3,966	5,303	4,354
Unpaid Principal Balance	4,193	5,513	4,516
Average Recorded Investment	5,228	5,738	4,982
Recognized Interest Income	180	239	162
Residential Construction
Composition of Loan Portfolio [Abstract]
Amount of loan portfolio	$ 8,451	$ 12,160	11,803
Percentage of loan portfolio (in hundredths)	0.90%	1.30%
Loans, aging disclosure [Abstract]
All Past Due	$ 368	$ 0
Current	8,083	12,160
Amount of loan portfolio	8,451	12,160	11,803
90 Plus Days And Accruing	0	0
Nonaccrual Loans [Abstract]
Nonaccrual loans	0	0
Average investment in impaired loans	0	0	0
Balance of impaired loans	0	0	0
Portion of allowance for loan losses allocated to the impaired loan balance	0	0	0
Recorded Investment	0	0	0
Unpaid Principal Balance	0	0	0
Average Recorded Investment	0	0	0
Recognized Interest Income	$ 0	$ 0	0
Troubled Debt Restructured, Number of Loans \| loan	0	0
Troubled Debt Restructured, Balance	$ 0	$ 0
Troubled Debt Restructured, Specific Reserves	$ 0	$ 0
Troubled Debt Restructured (Greater than 30 days), Number of Loans \| loan	0	0
Troubled Debt Restructured (Greater than 30 days), Balance	$ 0	$ 0
Troubled Debt Restructured (Greater than 30 days), Specific Reserves	$ 0	$ 0
Financing Receivable, Number of Loans \| loan	0	0
Financing Receivable, Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Financing Receivable, Post-Modification Outstanding Recorded Investment	0	0
Financing Receivable, Specific Reserves	0	0
Residential Construction \| 30-59 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	368	0
Residential Construction \| 60-89 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	0	0
Residential Construction \| 90 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	0	0
Residential Construction \| With No Related Allowance Recorded
Nonaccrual Loans [Abstract]
Average investment in impaired loans	0	0	0
Balance of impaired loans	0	0	0
Portion of allowance for loan losses allocated to the impaired loan balance	0	0	0
Recorded Investment	0	0	0
Unpaid Principal Balance	0	0	0
Average Recorded Investment	0	0	0
Recognized Interest Income	0	0	0
Residential Construction \| With an Allowance Recorded
Nonaccrual Loans [Abstract]
Average investment in impaired loans	0	0	0
Balance of impaired loans	0	0	0
Portion of allowance for loan losses allocated to the impaired loan balance	0	0	0
Recorded Investment	0	0	0
Unpaid Principal Balance	0	0	0
Average Recorded Investment	0	0	0
Recognized Interest Income	0	0	0
Home equity line of credit
Composition of Loan Portfolio [Abstract]
Amount of loan portfolio	$ 110,202	$ 103,521	91,549
Percentage of loan portfolio (in hundredths)	11.10%	11.30%
Loans, aging disclosure [Abstract]
All Past Due	$ 1,108	$ 2,122
Current	109,094	101,399
Amount of loan portfolio	110,202	103,521	91,549
90 Plus Days And Accruing	0	0
Nonaccrual Loans [Abstract]
Nonaccrual loans	893	832
Average investment in impaired loans	1,587	1,765	1,676
Balance of impaired loans	1,466	2,087	1,648
Portion of allowance for loan losses allocated to the impaired loan balance	29	396	54
Recorded Investment	1,466	2,087	1,648
Unpaid Principal Balance	2,120	2,324	1,884
Average Recorded Investment	1,587	1,765	1,676
Recognized Interest Income	$ 45	$ 46	34
Troubled Debt Restructured, Number of Loans \| loan	4	5
Troubled Debt Restructured, Balance	$ 742	$ 821
Troubled Debt Restructured, Specific Reserves	$ 0	$ 21
Troubled Debt Restructured (Greater than 30 days), Number of Loans \| loan	0	2
Troubled Debt Restructured (Greater than 30 days), Balance	$ 0	$ 226
Troubled Debt Restructured (Greater than 30 days), Specific Reserves	$ 0	$ 21
Financing Receivable, Number of Loans \| loan	0	0
Financing Receivable, Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Financing Receivable, Post-Modification Outstanding Recorded Investment	0	0
Financing Receivable, Specific Reserves	0	0
Home equity line of credit \| 30-59 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	261	622
Home equity line of credit \| 60-89 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	255	720
Home equity line of credit \| 90 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	592	780
Home equity line of credit \| With No Related Allowance Recorded
Nonaccrual Loans [Abstract]
Average investment in impaired loans	1,400	1,447	1,578
Balance of impaired loans	1,401	1,164	1,555
Portion of allowance for loan losses allocated to the impaired loan balance	0	0	0
Recorded Investment	1,401	1,164	1,555
Unpaid Principal Balance	2,054	1,395	1,791
Average Recorded Investment	1,400	1,447	1,578
Recognized Interest Income	43	29	32
Home equity line of credit \| With an Allowance Recorded
Nonaccrual Loans [Abstract]
Average investment in impaired loans	187	318	98
Balance of impaired loans	65	923	93
Portion of allowance for loan losses allocated to the impaired loan balance	29	396	54
Recorded Investment	65	923	93
Unpaid Principal Balance	66	929	93
Average Recorded Investment	187	318	98
Recognized Interest Income	3	17	2
Consumer
Composition of Loan Portfolio [Abstract]
Amount of loan portfolio	$ 24,520	$ 19,653
Percentage of loan portfolio (in hundredths)	2.50%	2.10%
Loans, aging disclosure [Abstract]
All Past Due	$ 139	$ 769
Current	24,381	18,884
Amount of loan portfolio	24,520	19,653
90 Plus Days And Accruing	11	80
Nonaccrual Loans [Abstract]
Nonaccrual loans	0	26
Average investment in impaired loans	42	11	0
Balance of impaired loans	0	26	0
Portion of allowance for loan losses allocated to the impaired loan balance	0	0	0
Recorded Investment	0	26	0
Unpaid Principal Balance	0	28	0
Average Recorded Investment	42	11	0
Recognized Interest Income	$ 3	$ 3	0
Troubled Debt Restructured, Number of Loans \| loan	0	0
Troubled Debt Restructured, Balance	$ 0	$ 0
Troubled Debt Restructured, Specific Reserves	$ 0	$ 0
Troubled Debt Restructured (Greater than 30 days), Number of Loans \| loan	0	0
Troubled Debt Restructured (Greater than 30 days), Balance	$ 0	$ 0
Troubled Debt Restructured (Greater than 30 days), Specific Reserves	$ 0	$ 0
Financing Receivable, Number of Loans \| loan	0	0
Financing Receivable, Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Financing Receivable, Post-Modification Outstanding Recorded Investment	0	0
Financing Receivable, Specific Reserves	0	0
Consumer \| 30-59 Days Past Due
Loans, aging disclosure [Abstract]
All Past Due	102	637
Consumer \| 60-89 Days Past Due
Loans, aging disclosure [Abstract]

-- None. No documentation exists for this element. --

No definition available.

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- Definition

Carrying amount of loans classified as troubled debt restructurings that are involved in bankruptcy as of the balance sheet date.

+ References

No definition available.

+ Details

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- Definition

Carrying amount of loans classified as troubled debt restructurings that were on non-accrual status as of the balance sheet date.

+ References

No definition available.

+ Details

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Namespace Prefix:	fnlc_
Data Type:	xbrli:monetaryItemType
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- Definition

Carrying amount of loans classified as troubled debt restructurings that had been placed on TDR status in previous 12 months.

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The number of financing receivables that have been modified by troubled debt restructurings during the current period.

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No definition available.

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The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings before the financing receivable has been modified during the current period.

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Financing Receivable, Number Of Loans Classified As Troubled Debt Restructurings Involved In Foreclosure

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The number of loans classified as troubled debt restructurings that were on non-accrual status as of the balance sheet date.

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Financing receivables that are greater than 30 days past due.

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Financing receivables that are greater than 30 days past due and that had been placed in TDR status in the previous 12 months.

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Financing Receivable, Recorded Investment, Greater than 30 Days Past Due, Placed in T D R in Previous 12 months, Specific Allowance during Period

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Portion of loans receivable balance which has an offsetting allowance for doubtful accounts.

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The portion of loans receivable balance which doesn't have an offsetting allowance for doubtful accounts.

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Loans classified as troubled debt restructurings that are involved in foreclosure as of the balance sheet date.

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Loans and Leases Receivables, Related Parties, Additions, Aggregated Over 60,000 Dollars

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Loans and Leases Receivables, Related Parties, Collections, Aggregated Over 60,000 Dollars

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Mortgage Loans in Process of Foreclosure, Number

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Reflects the break down of the gross carrying amount of all categories of loans and leases held in the portfolio, after deducting deferred income, but before deducting the allowance for losses on loans and leases as a percentage of total portfolio.

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For an unclassified balance sheet, reflects the carrying amount of unpaid loan amounts which in aggregate exceed $60,000, due from related parties at the balance sheet date.

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Specific allowance for loan and lease losses on receivable financings that are classified as troubled debt restructurings during the current period.

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Specific allowance for loan and lease losses on receivable financings that are classified as troubled debt restructurings during the period.

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For an unclassified balance sheet, amounts due from related parties including affiliates, employees, joint ventures, officers and stockholders, immediate families thereof, and pension funds.

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Amount of the collateral pledged in support of federal home loan bank advances outstanding.

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Post-modification amount of investment in financing receivables modified by troubled debt restructurings.

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Pre-modification amount of investment in financing receivables modified by troubled debt restructurings.

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Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

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Recorded investment in financing receivables that are 90 days or more past due and still accruing.

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Financing receivables that are current.

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Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

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Recorded Investment in financing receivables that are past due at the balance sheet date.

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

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Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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Amount of interest income recognized on a cash-basis method of accounting that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

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Amount of allowance for credit losses related to recorded investment.

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Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.

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Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

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Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period).

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Amount before allowance and after 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.

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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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Carrying amount as of the balance sheet date of loans that have been pledged as collateral for borrowings. If the secured party has the right by contract or custom to sell or re-pledge the collateral, then the debtor reclassifies that asset and report that asset in its statement of financial position separately from other assets not so encumbered.

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Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

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