XML 37 R61.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Loans (Details) (USD $) | 12 Months Ended
--- | ---
Dec. 31, 2014 loan | Dec. 31, 2013 loan | Dec. 31, 2012
Composition of Loan Portfolio [Abstract] |  |  |
Amount of loan portfolio | $ 917,564,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome | $ 876,367,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome | $ 869,284,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome
Percentage of loan portfolio (in hundredths) | 100.00%fnlc_PercentageOfLoansReceivableByType | 100.00%fnlc_PercentageOfLoansReceivableByType |
Loans Receivable to Related Party [Roll Forward] |  |  |
Balance at beginning of year | 14,884,000 fnlc_RelatedPartyLoanReceivableAggregatedOver60000Dollars | 14,917,000 fnlc_RelatedPartyLoanReceivableAggregatedOver60000Dollars |
New loans | 8,932,000 fnlc_LoansandLeasesReceivablesRelatedPartiesAdditionsAggregatedOver60000Dollars | 909,000 fnlc_LoansandLeasesReceivablesRelatedPartiesAdditionsAggregatedOver60000Dollars |
Repayments | (8,960,000)fnlc_LoansandLeasesReceivablesRelatedPartiesCollectionsAggregatedOver60000Dollars | (942,000)fnlc_LoansandLeasesReceivablesRelatedPartiesCollectionsAggregatedOver60000Dollars |
Balance at end of year | 14,856,000 fnlc_RelatedPartyLoanReceivableAggregatedOver60000Dollars | 14,884,000 fnlc_RelatedPartyLoanReceivableAggregatedOver60000Dollars | 14,917,000 fnlc_RelatedPartyLoanReceivableAggregatedOver60000Dollars
Loans, aging disclosure [Abstract] |  |  |
Loans Receivable 30 59 Days Past Due | 2,142,000 fnlc_LoansReceivable3059DaysPastDue | 1,588,000 fnlc_LoansReceivable3059DaysPastDue |
Loans Receivable 60 89 Days Past Due | 1,356,000 fnlc_LoansReceivable6089DaysPastDue | 2,471,000 fnlc_LoansReceivable6089DaysPastDue |
90 Plus Days Past Due | 8,365,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue | 11,933,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue |
All Past Due | 11,863,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue | 15,992,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue |
Current | 905,701,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent | 860,375,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent |
Amount of loan portfolio | 917,564,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome | 876,367,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome | 869,284,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome
90 Plus Days And Accruing | 181,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing | 1,043,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing |
Nonaccrual Loans [Abstract] |  |  |
Nonaccrual Loans Receivable | 10,510,000 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus | 16,318,000 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus |
Average investment in impaired loans | 38,404,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment | 45,722,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment | 45,019,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
Interest income recognized on impaired loans, all on cash basis | 1,465,000 us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod | 1,750,000 us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod | 1,039,000 us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod
Balance of impaired loans | 35,862,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment | 42,351,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment | 45,744,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment
Less portion for which no allowance for loan losses is allocated | (26,313,000)fnlc_ImpairedFinancingReceivableWithNoAllowance | (32,417,000)fnlc_ImpairedFinancingReceivableWithNoAllowance |
Portion of impaired loan balance for which an allowance for loan losses is allocated | 9,549,000 fnlc_ImpairedFinancingReceivableWithAllowance | 9,934,000 fnlc_ImpairedFinancingReceivableWithAllowance |
Portion of allowance for loan losses allocated to the impaired loan balance | 826,000 fnlc_FinancingReceivableModificationsPreModificationRecordedInvestmentDuringPeriod | 3,604,000 fnlc_FinancingReceivableModificationsPreModificationRecordedInvestmentDuringPeriod |
Recorded Investment | 35,862,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment | 42,351,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment | 45,744,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment
Unpaid Principal Balance | 39,026,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance | 46,408,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance | 49,542,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
Related Allowance | 1,803,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance | 2,461,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance | 3,539,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance
Average Recorded Investment | 38,404,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment | 45,722,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment | 45,019,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
Recognized Interest Income | 1,465,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod | 1,750,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod | 1,039,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
Troubled Debt Restructured, Number of Loans | 94 us-gaap_FinancingReceivableModificationsNumberOfContracts2 | 99 us-gaap_FinancingReceivableModificationsNumberOfContracts2 |
Troubled Debt Restructured, Balance | 27,214,000 us-gaap_FinancingReceivableModificationsRecordedInvestment | 29,098,000 us-gaap_FinancingReceivableModificationsRecordedInvestment |
Troubled Debt Restructured, Specific Reserves | 868,000 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceDuringPeriod | 1,017,000 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceDuringPeriod |
Troubled Debt Restructured (Greater than 30 days), Number of Loans | 12 fnlc_FinancingReceivableModificationsNumberOfContractsGreaterThan30DaysPastDuePlaceInTDRInPrevious12Months | 16 fnlc_FinancingReceivableModificationsNumberOfContractsGreaterThan30DaysPastDuePlaceInTDRInPrevious12Months |
Troubled Debt Restructured (Greater than 30 days), Balance | 1,549,000 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDuePlacedInTDRInPrevious12Months | 3,261,000 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDuePlacedInTDRInPrevious12Months |
Troubled Debt Restructured (Greater than 30 days), Specific Reserves | 177,000 fnlc_FinancingReceivableRecordedInvestmentGreaterthan30DaysPastDuePlacedinTDRinPrevious12monthsSpecificAllowanceduringPeriod | 37,000 fnlc_FinancingReceivableRecordedInvestmentGreaterthan30DaysPastDuePlacedinTDRinPrevious12monthsSpecificAllowanceduringPeriod |
Financing Receivable, Number of Loans | 6 fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod | 10 fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod |
Financing Receivable, Pre-Modification Outstanding Recorded Investment | 929,000 us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 | 3,610,000 us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 |
Financing Receivable, Post-Modification Outstanding Recorded Investment | 826,000 us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2 | 3,604,000 us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2 |
Financing Receivable, Specific Reserves | 12,000 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceCurrentPeriod | 31,000 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceCurrentPeriod |
Net deferred loan costs included in loan balances | 2,729,000 us-gaap_LoansAndLeasesReceivableDeferredIncome | 2,086,000 us-gaap_LoansAndLeasesReceivableDeferredIncome |
Loans used to collateralize borrowings from the Federal Home Loan Bank of Boston | 266,716,000 us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1 | 266,740,000 us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1 |
Commercial, construction and home equity loans used to collateralize unused line of credit at the Federal Reserve Bank of Boston | 240,943,000 us-gaap_LoansPledgedAsCollateral | 189,728,000 us-gaap_LoansPledgedAsCollateral |
Interest income which would have been recognized on these loans, if interest had been accrued | 551,000 us-gaap_LoansAndLeasesReceivableImpairedInterestLostOnNonaccrualLoans | 917,000 us-gaap_LoansAndLeasesReceivableImpairedInterestLostOnNonaccrualLoans | 1,158,000 us-gaap_LoansAndLeasesReceivableImpairedInterestLostOnNonaccrualLoans
Due from Related Parties | 29,883,000 us-gaap_DueFromRelatedParties | 28,821,000 us-gaap_DueFromRelatedParties |
Balance of loans classified as TDRs, greater than 30 days past due | 1,549,000 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDue | 3,261,000 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDue |
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | 2 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 | 6 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 |
Financing Receivable, Loans Classified as Troubled Debt Restructurings That Had Been Placed on TDR Status in Previous 12 Months | 238,000 fnlc_FinancingReceivableLoansClassifiedasTroubledDebtRestructuringsThatHadBeenPlacedonTDRStatusinPrevious12Months | 810,000 fnlc_FinancingReceivableLoansClassifiedasTroubledDebtRestructuringsThatHadBeenPlacedonTDRStatusinPrevious12Months |
Loans classified as TDRs that are involved in bankruptcy | 1,215,000 fnlc_FinancingReceivableLoansClassifiedAsTroubledDebtRestructuringsThatAreInvolvedInBankruptcy |  |
Number of loans classified as TDRs that were on non-accrual status | 16 fnlc_FinancingReceivableNumberOfLoansClassifiedAsTroubledDebtRestructuringsThatWereOnNonAccrualStatus |  |
Loans classified as TDRs that were on non-accrual status | 2,496,000 fnlc_FinancingReceivableLoansClassifiedAsTroubledDebtRestructuringsThatWereOnNonAccrualStatus |  |
Number of loans classified as TDRs that are involved in foreclosure | 5 fnlc_NumberOfLoansClassifiedAsTroubledDebtRestructuringsThatAreInvolvedInForeclosure |  |
Loans classified as TDRs that are involved in foreclosure | 611,000 fnlc_LoansClassifiedAsTroubledDebtRestructuringsThatAreInvolvedInForeclosure |  |
With an Allowance Recorded |  |  |
Nonaccrual Loans [Abstract] |  |  |
Average investment in impaired loans | 11,478,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 14,181,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 18,182,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Balance of impaired loans | 9,549,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 9,934,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 17,462,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Recorded Investment | 9,549,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 9,934,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 17,462,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Unpaid Principal Balance | 9,949,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 10,289,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 18,239,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Related Allowance | 1,803,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 2,461,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 3,539,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Average Recorded Investment | 11,478,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 14,181,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 18,182,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Recognized Interest Income | 387,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 390,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 571,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
With No Related Allowance Recorded |  |  |
Nonaccrual Loans [Abstract] |  |  |
Average investment in impaired loans | 26,926,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 31,541,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 26,837,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Balance of impaired loans | 26,313,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 32,417,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 28,282,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Recorded Investment | 26,313,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 32,417,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 28,282,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Unpaid Principal Balance | 29,077,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 36,119,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 31,303,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Related Allowance | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Average Recorded Investment | 26,926,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 31,541,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 26,837,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Recognized Interest Income | 1,078,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 1,360,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 468,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Commercial Real Estate Other Receivable |  |  |
Nonaccrual Loans [Abstract] |  |  |
Troubled Debt Restructured, Number of Loans | 15 us-gaap_FinancingReceivableModificationsNumberOfContracts2 / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateOtherReceivableMember | 20 us-gaap_FinancingReceivableModificationsNumberOfContracts2 / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateOtherReceivableMember |
Troubled Debt Restructured, Balance | 2,007,000 us-gaap_FinancingReceivableModificationsRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateOtherReceivableMember | 2,734,000 us-gaap_FinancingReceivableModificationsRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateOtherReceivableMember |
Troubled Debt Restructured, Specific Reserves | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceDuringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateOtherReceivableMember | 100,000 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceDuringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateOtherReceivableMember |
Troubled Debt Restructured (Greater than 30 days), Number of Loans | 1 fnlc_FinancingReceivableModificationsNumberOfContractsGreaterThan30DaysPastDuePlaceInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateOtherReceivableMember | 2 fnlc_FinancingReceivableModificationsNumberOfContractsGreaterThan30DaysPastDuePlaceInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateOtherReceivableMember |
Troubled Debt Restructured (Greater than 30 days), Balance | 2,000 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDuePlacedInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateOtherReceivableMember | 355,000 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDuePlacedInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateOtherReceivableMember |
Troubled Debt Restructured (Greater than 30 days), Specific Reserves | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterthan30DaysPastDuePlacedinTDRinPrevious12monthsSpecificAllowanceduringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateOtherReceivableMember | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterthan30DaysPastDuePlacedinTDRinPrevious12monthsSpecificAllowanceduringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateOtherReceivableMember |
Commercial Real Estate |  |  |
Nonaccrual Loans [Abstract] |  |  |
Troubled Debt Restructured, Number of Loans | 19 us-gaap_FinancingReceivableModificationsNumberOfContracts2 / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateMember | 20 us-gaap_FinancingReceivableModificationsNumberOfContracts2 / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateMember |
Troubled Debt Restructured, Balance | 12,282,000 us-gaap_FinancingReceivableModificationsRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateMember | 13,018,000 us-gaap_FinancingReceivableModificationsRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateMember |
Troubled Debt Restructured, Specific Reserves | 267,000 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceDuringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateMember | 433,000 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceDuringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateMember |
Troubled Debt Restructured (Greater than 30 days), Number of Loans | 1 fnlc_FinancingReceivableModificationsNumberOfContractsGreaterThan30DaysPastDuePlaceInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateMember | 2 fnlc_FinancingReceivableModificationsNumberOfContractsGreaterThan30DaysPastDuePlaceInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateMember |
Troubled Debt Restructured (Greater than 30 days), Balance | 321,000 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDuePlacedInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateMember | 990,000 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDuePlacedInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateMember |
Troubled Debt Restructured (Greater than 30 days), Specific Reserves | 120,000 fnlc_FinancingReceivableRecordedInvestmentGreaterthan30DaysPastDuePlacedinTDRinPrevious12monthsSpecificAllowanceduringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateMember | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterthan30DaysPastDuePlacedinTDRinPrevious12monthsSpecificAllowanceduringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateMember |
Commercial Construction |  |  |
Nonaccrual Loans [Abstract] |  |  |
Troubled Debt Restructured, Number of Loans | 1 us-gaap_FinancingReceivableModificationsNumberOfContracts2 / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 1 us-gaap_FinancingReceivableModificationsNumberOfContracts2 / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |
Troubled Debt Restructured, Balance | 1,172,000 us-gaap_FinancingReceivableModificationsRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 1,284,000 us-gaap_FinancingReceivableModificationsRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |
Troubled Debt Restructured, Specific Reserves | 207,000 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceDuringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 274,000 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceDuringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |
Troubled Debt Restructured (Greater than 30 days), Number of Loans | 0 fnlc_FinancingReceivableModificationsNumberOfContractsGreaterThan30DaysPastDuePlaceInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 0 fnlc_FinancingReceivableModificationsNumberOfContractsGreaterThan30DaysPastDuePlaceInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |
Troubled Debt Restructured (Greater than 30 days), Balance | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDuePlacedInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDuePlacedInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |
Troubled Debt Restructured (Greater than 30 days), Specific Reserves | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterthan30DaysPastDuePlacedinTDRinPrevious12monthsSpecificAllowanceduringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterthan30DaysPastDuePlacedinTDRinPrevious12monthsSpecificAllowanceduringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |
Municipal |  |  |
Nonaccrual Loans [Abstract] |  |  |
Troubled Debt Restructured, Number of Loans | 0 us-gaap_FinancingReceivableModificationsNumberOfContracts2 / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_MunicipalMember | 0 us-gaap_FinancingReceivableModificationsNumberOfContracts2 / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_MunicipalMember |
Troubled Debt Restructured, Balance | 0 us-gaap_FinancingReceivableModificationsRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_MunicipalMember | 0 us-gaap_FinancingReceivableModificationsRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_MunicipalMember |
Troubled Debt Restructured, Specific Reserves | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceDuringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_MunicipalMember | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceDuringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_MunicipalMember |
Residential Term |  |  |
Nonaccrual Loans [Abstract] |  |  |
Troubled Debt Restructured, Number of Loans | 54 us-gaap_FinancingReceivableModificationsNumberOfContracts2 / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialTermMember | 53 us-gaap_FinancingReceivableModificationsNumberOfContracts2 / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialTermMember |
Troubled Debt Restructured, Balance | 10,932,000 us-gaap_FinancingReceivableModificationsRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialTermMember | 11,220,000 us-gaap_FinancingReceivableModificationsRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialTermMember |
Troubled Debt Restructured, Specific Reserves | 373,000 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceDuringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialTermMember | 210,000 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceDuringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialTermMember |
Troubled Debt Restructured (Greater than 30 days), Number of Loans | 8 fnlc_FinancingReceivableModificationsNumberOfContractsGreaterThan30DaysPastDuePlaceInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialTermMember | 10 fnlc_FinancingReceivableModificationsNumberOfContractsGreaterThan30DaysPastDuePlaceInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialTermMember |
Troubled Debt Restructured (Greater than 30 days), Balance | 1,000,000 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDuePlacedInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialTermMember | 1,688,000 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDuePlacedInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialTermMember |
Troubled Debt Restructured (Greater than 30 days), Specific Reserves | 36,000 fnlc_FinancingReceivableRecordedInvestmentGreaterthan30DaysPastDuePlacedinTDRinPrevious12monthsSpecificAllowanceduringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialTermMember | 37,000 fnlc_FinancingReceivableRecordedInvestmentGreaterthan30DaysPastDuePlacedinTDRinPrevious12monthsSpecificAllowanceduringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialTermMember |
Residential Construction |  |  |
Nonaccrual Loans [Abstract] |  |  |
Troubled Debt Restructured, Number of Loans | 0 us-gaap_FinancingReceivableModificationsNumberOfContracts2 / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialConstructionMember | 0 us-gaap_FinancingReceivableModificationsNumberOfContracts2 / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialConstructionMember |
Troubled Debt Restructured, Balance | 0 us-gaap_FinancingReceivableModificationsRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialConstructionMember | 0 us-gaap_FinancingReceivableModificationsRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialConstructionMember |
Troubled Debt Restructured, Specific Reserves | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceDuringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialConstructionMember | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceDuringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialConstructionMember |
Troubled Debt Restructured (Greater than 30 days), Number of Loans | 0 fnlc_FinancingReceivableModificationsNumberOfContractsGreaterThan30DaysPastDuePlaceInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialConstructionMember | 0 fnlc_FinancingReceivableModificationsNumberOfContractsGreaterThan30DaysPastDuePlaceInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialConstructionMember |
Troubled Debt Restructured (Greater than 30 days), Balance | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDuePlacedInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialConstructionMember | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDuePlacedInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialConstructionMember |
Troubled Debt Restructured (Greater than 30 days), Specific Reserves | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterthan30DaysPastDuePlacedinTDRinPrevious12monthsSpecificAllowanceduringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialConstructionMember | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterthan30DaysPastDuePlacedinTDRinPrevious12monthsSpecificAllowanceduringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_ResidentialConstructionMember |
Home equity line of credit |  |  |
Nonaccrual Loans [Abstract] |  |  |
Troubled Debt Restructured, Number of Loans | 5 us-gaap_FinancingReceivableModificationsNumberOfContracts2 / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_HomeEquityMember | 5 us-gaap_FinancingReceivableModificationsNumberOfContracts2 / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_HomeEquityMember |
Troubled Debt Restructured, Balance | 821,000 us-gaap_FinancingReceivableModificationsRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_HomeEquityMember | 842,000 us-gaap_FinancingReceivableModificationsRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_HomeEquityMember |
Troubled Debt Restructured, Specific Reserves | 21,000 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceDuringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_HomeEquityMember | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceDuringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_HomeEquityMember |
Troubled Debt Restructured (Greater than 30 days), Number of Loans | 2 fnlc_FinancingReceivableModificationsNumberOfContractsGreaterThan30DaysPastDuePlaceInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_HomeEquityMember | 2 fnlc_FinancingReceivableModificationsNumberOfContractsGreaterThan30DaysPastDuePlaceInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_HomeEquityMember |
Troubled Debt Restructured (Greater than 30 days), Balance | 226,000 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDuePlacedInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_HomeEquityMember | 228,000 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDuePlacedInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_HomeEquityMember |
Troubled Debt Restructured (Greater than 30 days), Specific Reserves | 21,000 fnlc_FinancingReceivableRecordedInvestmentGreaterthan30DaysPastDuePlacedinTDRinPrevious12monthsSpecificAllowanceduringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_HomeEquityMember | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterthan30DaysPastDuePlacedinTDRinPrevious12monthsSpecificAllowanceduringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_HomeEquityMember |
Consumer |  |  |
Nonaccrual Loans [Abstract] |  |  |
Troubled Debt Restructured, Number of Loans | 0 us-gaap_FinancingReceivableModificationsNumberOfContracts2 / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_ConsumerLoanMember | 0 us-gaap_FinancingReceivableModificationsNumberOfContracts2 / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_ConsumerLoanMember |
Troubled Debt Restructured, Balance | 0 us-gaap_FinancingReceivableModificationsRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_ConsumerLoanMember | 0 us-gaap_FinancingReceivableModificationsRecordedInvestment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_ConsumerLoanMember |
Troubled Debt Restructured, Specific Reserves | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceDuringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_ConsumerLoanMember | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceDuringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_ConsumerLoanMember |
Troubled Debt Restructured (Greater than 30 days), Number of Loans | 0 fnlc_FinancingReceivableModificationsNumberOfContractsGreaterThan30DaysPastDuePlaceInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_ConsumerLoanMember | 0 fnlc_FinancingReceivableModificationsNumberOfContractsGreaterThan30DaysPastDuePlaceInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_ConsumerLoanMember |
Troubled Debt Restructured (Greater than 30 days), Balance | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDuePlacedInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_ConsumerLoanMember | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDuePlacedInTDRInPrevious12Months / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_ConsumerLoanMember |
Troubled Debt Restructured (Greater than 30 days), Specific Reserves | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterthan30DaysPastDuePlacedinTDRinPrevious12monthsSpecificAllowanceduringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_ConsumerLoanMember | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterthan30DaysPastDuePlacedinTDRinPrevious12monthsSpecificAllowanceduringPeriod / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_ConsumerLoanMember |
Commercial Other |  |  |
Composition of Loan Portfolio [Abstract] |  |  |
Amount of loan portfolio | 104,531,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 95,289,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 81,183,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember
Percentage of loan portfolio (in hundredths) | 11.40%fnlc_PercentageOfLoansReceivableByType / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 10.90%fnlc_PercentageOfLoansReceivableByType / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember |
Loans, aging disclosure [Abstract] |  |  |
Loans Receivable 30 59 Days Past Due | 3,000 fnlc_LoansReceivable3059DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 544,000 fnlc_LoansReceivable3059DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember |
Loans Receivable 60 89 Days Past Due | 0 fnlc_LoansReceivable6089DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 128,000 fnlc_LoansReceivable6089DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember |
90 Plus Days Past Due | 857,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 2,797,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember |
All Past Due | 860,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 3,469,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember |
Current | 103,671,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 91,820,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember |
Amount of loan portfolio | 104,531,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 95,289,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 81,183,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember
90 Plus Days And Accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember |
Nonaccrual Loans [Abstract] |  |  |
Nonaccrual Loans Receivable | 935,000 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 4,370,000 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember |
Average investment in impaired loans | 4,956,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 5,898,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 4,851,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember
Balance of impaired loans | 2,942,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 6,698,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 5,861,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember
Recorded Investment | 2,942,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 6,698,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 5,861,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember
Unpaid Principal Balance | 3,745,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 8,441,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 6,471,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember
Related Allowance | 129,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 841,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 652,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember
Average Recorded Investment | 4,956,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 5,898,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 4,851,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember
Recognized Interest Income | 169,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 350,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember | 91,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember
Financing Receivable, Number of Loans |  | 2 fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember |
Financing Receivable, Pre-Modification Outstanding Recorded Investment |  | 491,000 us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember |
Financing Receivable, Post-Modification Outstanding Recorded Investment |  | 491,000 us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember |
Financing Receivable, Specific Reserves |  | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceCurrentPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember |
Commercial Other | With an Allowance Recorded |  |  |
Nonaccrual Loans [Abstract] |  |  |
Average investment in impaired loans | 1,103,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 1,633,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 1,974,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Balance of impaired loans | 326,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 1,081,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 1,124,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Recorded Investment | 326,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 1,081,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 1,124,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Unpaid Principal Balance | 338,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 1,132,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 1,126,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Related Allowance | 129,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 841,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 652,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Average Recorded Investment | 1,103,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 1,633,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 1,974,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Recognized Interest Income | 13,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 28,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 38,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Commercial Other | With No Related Allowance Recorded |  |  |
Nonaccrual Loans [Abstract] |  |  |
Average investment in impaired loans | 3,853,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 4,265,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 2,877,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Balance of impaired loans | 2,616,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 5,617,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 4,737,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Recorded Investment | 2,616,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 5,617,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 4,737,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Unpaid Principal Balance | 3,407,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 7,309,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 5,345,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Related Allowance | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Average Recorded Investment | 3,853,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 4,265,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 2,877,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Recognized Interest Income | 156,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 322,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 53,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialOtherMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Commercial Real Estate Other Receivable |  |  |
Nonaccrual Loans [Abstract] |  |  |
Financing Receivable, Number of Loans | 0 fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateOtherReceivableMember |  |
Financing Receivable, Pre-Modification Outstanding Recorded Investment | 0 us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateOtherReceivableMember |  |
Financing Receivable, Post-Modification Outstanding Recorded Investment | 0 us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateOtherReceivableMember |  |
Financing Receivable, Specific Reserves | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceCurrentPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateOtherReceivableMember |  |
Consumer Portfolio Segment |  |  |
Composition of Loan Portfolio [Abstract] |  |  |
Amount of loan portfolio | 19,653,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember | 15,066,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember | 14,657,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember
Loans, aging disclosure [Abstract] |  |  |
Amount of loan portfolio | 19,653,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember | 15,066,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember | 14,657,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember
Nonaccrual Loans [Abstract] |  |  |
Financing Receivable, Number of Loans | 0 fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember | 0 fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember |
Financing Receivable, Pre-Modification Outstanding Recorded Investment | 0 us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember | 0 us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember |
Financing Receivable, Post-Modification Outstanding Recorded Investment | 0 us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember | 0 us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember |
Financing Receivable, Specific Reserves | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceCurrentPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceCurrentPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerPortfolioSegmentMember |
Commercial Construction |  |  |
Composition of Loan Portfolio [Abstract] |  |  |
Amount of loan portfolio | 30,932,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialConstructionMember | 20,382,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialConstructionMember | 22,417,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialConstructionMember
Loans, aging disclosure [Abstract] |  |  |
Amount of loan portfolio | 30,932,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialConstructionMember | 20,382,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialConstructionMember | 22,417,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialConstructionMember
Nonaccrual Loans [Abstract] |  |  |
Financing Receivable, Number of Loans | 0 fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialConstructionMember | 0 fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialConstructionMember |
Financing Receivable, Pre-Modification Outstanding Recorded Investment | 0 us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialConstructionMember | 0 us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialConstructionMember |
Financing Receivable, Post-Modification Outstanding Recorded Investment | 0 us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialConstructionMember | 0 us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialConstructionMember |
Financing Receivable, Specific Reserves | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceCurrentPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialConstructionMember | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceCurrentPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_CommercialConstructionMember |
Commercial Real Estate Portfolio Segment |  |  |
Composition of Loan Portfolio [Abstract] |  |  |
Amount of loan portfolio | 242,311,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember | 245,943,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember | 251,335,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Loans, aging disclosure [Abstract] |  |  |
Amount of loan portfolio | 242,311,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember | 245,943,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember | 251,335,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember
Nonaccrual Loans [Abstract] |  |  |
Financing Receivable, Number of Loans | 2 fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember | 2 fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember |
Financing Receivable, Pre-Modification Outstanding Recorded Investment | 302,000 us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember | 1,883,000 us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember |
Financing Receivable, Post-Modification Outstanding Recorded Investment | 300,000 us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember | 1,883,000 us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember |
Financing Receivable, Specific Reserves | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceCurrentPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceCurrentPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstatePortfolioSegmentMember |
Commercial Real Estate |  |  |
Composition of Loan Portfolio [Abstract] |  |  |
Amount of loan portfolio | 242,311,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 245,943,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember |
Percentage of loan portfolio (in hundredths) | 26.40%fnlc_PercentageOfLoansReceivableByType / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 28.20%fnlc_PercentageOfLoansReceivableByType / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember |
Loans, aging disclosure [Abstract] |  |  |
Loans Receivable 30 59 Days Past Due | 24,000 fnlc_LoansReceivable3059DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 82,000 fnlc_LoansReceivable3059DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember |
Loans Receivable 60 89 Days Past Due | 75,000 fnlc_LoansReceivable6089DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 259,000 fnlc_LoansReceivable6089DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember |
90 Plus Days Past Due | 761,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 745,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember |
All Past Due | 860,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 1,086,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember |
Current | 241,451,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 244,857,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember |
Amount of loan portfolio | 242,311,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 245,943,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember |
90 Plus Days And Accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember |
Nonaccrual Loans [Abstract] |  |  |
Nonaccrual Loans Receivable | 2,088,000 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 2,457,000 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember |
Average investment in impaired loans | 14,120,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 16,773,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 14,716,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember
Balance of impaired loans | 13,304,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 14,935,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 15,774,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember
Recorded Investment | 13,304,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 14,935,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 15,774,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember
Unpaid Principal Balance | 14,212,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 15,683,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 16,981,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember
Related Allowance | 346,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 890,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 1,523,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember
Average Recorded Investment | 14,120,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 16,773,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 14,716,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember
Recognized Interest Income | 550,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 645,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember | 410,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember
Commercial Real Estate | With an Allowance Recorded |  |  |
Nonaccrual Loans [Abstract] |  |  |
Average investment in impaired loans | 3,040,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 5,673,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 4,614,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Balance of impaired loans | 1,617,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 3,122,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 6,388,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Recorded Investment | 1,617,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 3,122,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 6,388,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Unpaid Principal Balance | 1,789,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 3,264,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 7,018,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Related Allowance | 346,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 890,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 1,523,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Average Recorded Investment | 3,040,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 5,673,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 4,614,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Recognized Interest Income | 62,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 150,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 211,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Commercial Real Estate | With No Related Allowance Recorded |  |  |
Nonaccrual Loans [Abstract] |  |  |
Average investment in impaired loans | 11,080,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 11,100,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 10,102,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Balance of impaired loans | 11,687,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 11,813,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 9,386,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Recorded Investment | 11,687,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 11,813,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 9,386,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Unpaid Principal Balance | 12,423,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 12,419,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 9,963,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Related Allowance | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Average Recorded Investment | 11,080,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 11,100,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 10,102,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Recognized Interest Income | 488,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 495,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 199,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Commercial Construction |  |  |
Composition of Loan Portfolio [Abstract] |  |  |
Amount of loan portfolio | 30,932,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 20,382,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |
Percentage of loan portfolio (in hundredths) | 3.40%fnlc_PercentageOfLoansReceivableByType / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 2.30%fnlc_PercentageOfLoansReceivableByType / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |
Loans, aging disclosure [Abstract] |  |  |
Loans Receivable 30 59 Days Past Due | 0 fnlc_LoansReceivable3059DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 0 fnlc_LoansReceivable3059DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |
Loans Receivable 60 89 Days Past Due | 41,000 fnlc_LoansReceivable6089DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 0 fnlc_LoansReceivable6089DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |
90 Plus Days Past Due | 208,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 0 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |
All Past Due | 249,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 0 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |
Current | 30,683,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 20,382,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |
Amount of loan portfolio | 30,932,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 20,382,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |
90 Plus Days And Accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |
Nonaccrual Loans [Abstract] |  |  |
Nonaccrual Loans Receivable | 208,000 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 0 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember |
Average investment in impaired loans | 1,309,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 1,997,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 4,349,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
Balance of impaired loans | 1,380,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 1,284,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 3,354,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
Recorded Investment | 1,380,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 1,284,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 3,354,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
Unpaid Principal Balance | 1,380,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 1,284,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 3,368,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
Related Allowance | 413,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 272,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 969,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
Average Recorded Investment | 1,309,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 1,997,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 4,349,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
Recognized Interest Income | 56,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 48,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember | 85,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
Commercial Construction | With an Allowance Recorded |  |  |
Nonaccrual Loans [Abstract] |  |  |
Average investment in impaired loans | 1,279,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 1,795,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 1,816,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Balance of impaired loans | 1,380,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 1,284,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 3,253,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Recorded Investment | 1,380,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 1,284,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 3,253,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Unpaid Principal Balance | 1,380,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 1,284,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 3,253,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Related Allowance | 413,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 272,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 969,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Average Recorded Investment | 1,279,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 1,795,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 1,816,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Recognized Interest Income | 56,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 48,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 85,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Commercial Construction | With No Related Allowance Recorded |  |  |
Nonaccrual Loans [Abstract] |  |  |
Average investment in impaired loans | 30,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 202,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 2,533,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Balance of impaired loans | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 101,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Recorded Investment | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 101,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Unpaid Principal Balance | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 115,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Related Allowance | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Average Recorded Investment | 30,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 202,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 2,533,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Recognized Interest Income | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialRealEstateConstructionFinancingReceivableMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Municipal |  |  |
Composition of Loan Portfolio [Abstract] |  |  |
Amount of loan portfolio | 20,424,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 19,117,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 14,704,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember
Percentage of loan portfolio (in hundredths) | 2.20%fnlc_PercentageOfLoansReceivableByType / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 2.20%fnlc_PercentageOfLoansReceivableByType / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember |
Loans, aging disclosure [Abstract] |  |  |
Loans Receivable 30 59 Days Past Due | 0 fnlc_LoansReceivable3059DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 fnlc_LoansReceivable3059DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember |
Loans Receivable 60 89 Days Past Due | 0 fnlc_LoansReceivable6089DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 fnlc_LoansReceivable6089DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember |
90 Plus Days Past Due | 0 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember |
All Past Due | 0 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember |
Current | 20,424,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 19,117,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember |
Amount of loan portfolio | 20,424,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 19,117,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 14,704,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember
90 Plus Days And Accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember |
Nonaccrual Loans [Abstract] |  |  |
Nonaccrual Loans Receivable | 0 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember |
Average investment in impaired loans | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember
Balance of impaired loans | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember
Recorded Investment | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember
Unpaid Principal Balance | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember
Related Allowance | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember
Average Recorded Investment | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember
Recognized Interest Income | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember
Troubled Debt Restructured (Greater than 30 days), Number of Loans | 0 fnlc_FinancingReceivableModificationsNumberOfContractsGreaterThan30DaysPastDuePlaceInTDRInPrevious12Months / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 fnlc_FinancingReceivableModificationsNumberOfContractsGreaterThan30DaysPastDuePlaceInTDRInPrevious12Months / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember |
Troubled Debt Restructured (Greater than 30 days), Balance | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDuePlacedInTDRInPrevious12Months / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDuePlacedInTDRInPrevious12Months / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember |
Troubled Debt Restructured (Greater than 30 days), Specific Reserves | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterthan30DaysPastDuePlacedinTDRinPrevious12monthsSpecificAllowanceduringPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 fnlc_FinancingReceivableRecordedInvestmentGreaterthan30DaysPastDuePlacedinTDRinPrevious12monthsSpecificAllowanceduringPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember |
Financing Receivable, Number of Loans | 0 fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember |
Financing Receivable, Pre-Modification Outstanding Recorded Investment | 0 us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember |
Financing Receivable, Post-Modification Outstanding Recorded Investment | 0 us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember |
Financing Receivable, Specific Reserves | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceCurrentPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceCurrentPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember |
Municipal | With an Allowance Recorded |  |  |
Nonaccrual Loans [Abstract] |  |  |
Average investment in impaired loans | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Balance of impaired loans | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Recorded Investment | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Unpaid Principal Balance | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Related Allowance | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Average Recorded Investment | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Recognized Interest Income | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Municipal | With No Related Allowance Recorded |  |  |
Nonaccrual Loans [Abstract] |  |  |
Average investment in impaired loans | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Balance of impaired loans | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Recorded Investment | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Unpaid Principal Balance | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Related Allowance | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Average Recorded Investment | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Recognized Interest Income | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_MunicipalMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Residential Term |  |  |
Composition of Loan Portfolio [Abstract] |  |  |
Amount of loan portfolio | 384,032,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 377,218,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 379,447,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember
Percentage of loan portfolio (in hundredths) | 41.90%fnlc_PercentageOfLoansReceivableByType / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 43.00%fnlc_PercentageOfLoansReceivableByType / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember |
Loans, aging disclosure [Abstract] |  |  |
Loans Receivable 30 59 Days Past Due | 856,000 fnlc_LoansReceivable3059DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 229,000 fnlc_LoansReceivable3059DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember |
Loans Receivable 60 89 Days Past Due | 468,000 fnlc_LoansReceivable6089DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 1,913,000 fnlc_LoansReceivable6089DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember |
90 Plus Days Past Due | 5,679,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 7,002,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember |
All Past Due | 7,003,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 9,144,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember |
Current | 377,029,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 368,074,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember |
Amount of loan portfolio | 384,032,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 377,218,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 379,447,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember
90 Plus Days And Accruing | 101,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 596,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember |
Nonaccrual Loans [Abstract] |  |  |
Nonaccrual Loans Receivable | 6,421,000 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 8,484,000 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember |
Average investment in impaired loans | 16,243,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 19,378,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 18,867,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember
Balance of impaired loans | 16,123,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 17,786,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 19,444,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember
Recorded Investment | 16,123,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 17,786,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 19,444,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember
Unpaid Principal Balance | 17,337,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 19,116,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 21,282,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember
Related Allowance | 519,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 404,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 395,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember
Average Recorded Investment | 16,243,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 19,378,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 18,867,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember
Recognized Interest Income | 641,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 673,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 426,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember
Financing Receivable, Number of Loans | 4 fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 5 fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember |
Financing Receivable, Pre-Modification Outstanding Recorded Investment | 627,000 us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 1,032,000 us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember |
Financing Receivable, Post-Modification Outstanding Recorded Investment | 526,000 us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 1,029,000 us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember |
Financing Receivable, Specific Reserves | 12,000 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceCurrentPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember | 31,000 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceCurrentPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember |
Residential Term | With an Allowance Recorded |  |  |
Nonaccrual Loans [Abstract] |  |  |
Average investment in impaired loans | 5,738,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 4,982,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 9,066,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Balance of impaired loans | 5,303,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 4,354,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 6,697,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Recorded Investment | 5,303,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 4,354,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 6,697,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Unpaid Principal Balance | 5,513,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 4,516,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 6,842,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Related Allowance | 519,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 404,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 395,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Average Recorded Investment | 5,738,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 4,982,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 9,066,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Recognized Interest Income | 239,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 162,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 237,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Residential Term | With No Related Allowance Recorded |  |  |
Nonaccrual Loans [Abstract] |  |  |
Average investment in impaired loans | 10,505,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 14,396,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 9,801,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Balance of impaired loans | 10,820,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 13,432,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 12,747,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Recorded Investment | 10,820,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 13,432,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 12,747,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Unpaid Principal Balance | 11,824,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 14,600,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 14,440,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Related Allowance | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Average Recorded Investment | 10,505,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 14,396,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 9,801,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Recognized Interest Income | 402,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 511,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 189,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialTermMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Residential Construction |  |  |
Composition of Loan Portfolio [Abstract] |  |  |
Amount of loan portfolio | 12,160,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 11,803,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 6,459,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember
Percentage of loan portfolio (in hundredths) | 1.30%fnlc_PercentageOfLoansReceivableByType / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 1.30%fnlc_PercentageOfLoansReceivableByType / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember |
Loans, aging disclosure [Abstract] |  |  |
Loans Receivable 30 59 Days Past Due | 0 fnlc_LoansReceivable3059DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 47,000 fnlc_LoansReceivable3059DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember |
Loans Receivable 60 89 Days Past Due | 0 fnlc_LoansReceivable6089DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 fnlc_LoansReceivable6089DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember |
90 Plus Days Past Due | 0 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember |
All Past Due | 0 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 47,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember |
Current | 12,160,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 11,756,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember |
Amount of loan portfolio | 12,160,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 11,803,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 6,459,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember
90 Plus Days And Accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember |
Nonaccrual Loans [Abstract] |  |  |
Nonaccrual Loans Receivable | 0 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember |
Average investment in impaired loans | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 821,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember
Balance of impaired loans | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember
Recorded Investment | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember
Unpaid Principal Balance | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember
Related Allowance | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember
Average Recorded Investment | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 821,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember
Recognized Interest Income | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember
Financing Receivable, Number of Loans | 0 fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember |
Financing Receivable, Pre-Modification Outstanding Recorded Investment | 0 us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember |
Financing Receivable, Post-Modification Outstanding Recorded Investment | 0 us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember |
Financing Receivable, Specific Reserves | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceCurrentPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceCurrentPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember |
Residential Construction | With an Allowance Recorded |  |  |
Nonaccrual Loans [Abstract] |  |  |
Average investment in impaired loans | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 261,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Balance of impaired loans | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Recorded Investment | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Unpaid Principal Balance | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Related Allowance | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Average Recorded Investment | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 261,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Recognized Interest Income | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Residential Construction | With No Related Allowance Recorded |  |  |
Nonaccrual Loans [Abstract] |  |  |
Average investment in impaired loans | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 560,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Balance of impaired loans | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Recorded Investment | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Unpaid Principal Balance | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Related Allowance | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Average Recorded Investment | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 560,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Recognized Interest Income | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = fnlc_ResidentialConstructionMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Home equity line of credit |  |  |
Composition of Loan Portfolio [Abstract] |  |  |
Amount of loan portfolio | 103,521,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 91,549,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 99,082,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember
Percentage of loan portfolio (in hundredths) | 11.30%fnlc_PercentageOfLoansReceivableByType / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 10.40%fnlc_PercentageOfLoansReceivableByType / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember |
Loans, aging disclosure [Abstract] |  |  |
Loans Receivable 30 59 Days Past Due | 622,000 fnlc_LoansReceivable3059DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 573,000 fnlc_LoansReceivable3059DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember |
Loans Receivable 60 89 Days Past Due | 720,000 fnlc_LoansReceivable6089DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 145,000 fnlc_LoansReceivable6089DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember |
90 Plus Days Past Due | 780,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 1,001,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember |
All Past Due | 2,122,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 1,719,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember |
Current | 101,399,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 89,830,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember |
Amount of loan portfolio | 103,521,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 91,549,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 99,082,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember
90 Plus Days And Accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 59,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember |
Nonaccrual Loans [Abstract] |  |  |
Nonaccrual Loans Receivable | 832,000 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 1,007,000 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember |
Average investment in impaired loans | 1,765,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 1,676,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 1,403,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember
Balance of impaired loans | 2,087,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 1,648,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 1,311,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember
Recorded Investment | 2,087,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 1,648,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 1,311,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember
Unpaid Principal Balance | 2,324,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 1,884,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 1,440,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember
Related Allowance | 396,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 54,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember
Average Recorded Investment | 1,765,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 1,676,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 1,403,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember
Recognized Interest Income | 46,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 34,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 27,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember
Financing Receivable, Number of Loans | 0 fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 1 fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember |
Financing Receivable, Pre-Modification Outstanding Recorded Investment | 0 us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 204,000 us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember |
Financing Receivable, Post-Modification Outstanding Recorded Investment | 0 us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 201,000 us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2 / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember |
Financing Receivable, Specific Reserves | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceCurrentPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember | 0 fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceCurrentPeriod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember |
Home equity line of credit | With an Allowance Recorded |  |  |
Nonaccrual Loans [Abstract] |  |  |
Average investment in impaired loans | 318,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 98,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 442,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Balance of impaired loans | 923,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 93,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Recorded Investment | 923,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 93,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Unpaid Principal Balance | 929,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 93,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Related Allowance | 396,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 54,000 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Average Recorded Investment | 318,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 98,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 442,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Recognized Interest Income | 17,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 2,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Home equity line of credit | With No Related Allowance Recorded |  |  |
Nonaccrual Loans [Abstract] |  |  |
Average investment in impaired loans | 1,447,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 1,578,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 961,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Balance of impaired loans | 1,164,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 1,555,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 1,311,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Recorded Investment | 1,164,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 1,555,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 1,311,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Unpaid Principal Balance | 1,395,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 1,791,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 1,440,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Related Allowance | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Average Recorded Investment | 1,447,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 1,578,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 961,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Recognized Interest Income | 29,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 32,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 27,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_HomeEquityMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Consumer |  |  |
Composition of Loan Portfolio [Abstract] |  |  |
Amount of loan portfolio | 19,653,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 15,066,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember |
Percentage of loan portfolio (in hundredths) | 2.10%fnlc_PercentageOfLoansReceivableByType / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 1.70%fnlc_PercentageOfLoansReceivableByType / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember |
Loans, aging disclosure [Abstract] |  |  |
Loans Receivable 30 59 Days Past Due | 637,000 fnlc_LoansReceivable3059DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 113,000 fnlc_LoansReceivable3059DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember |
Loans Receivable 60 89 Days Past Due | 52,000 fnlc_LoansReceivable6089DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 26,000 fnlc_LoansReceivable6089DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember |
90 Plus Days Past Due | 80,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 388,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember |
All Past Due | 769,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 527,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember |
Current | 18,884,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 14,539,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember |
Amount of loan portfolio | 19,653,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 15,066,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember |
90 Plus Days And Accruing | 80,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 388,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember |
Nonaccrual Loans [Abstract] |  |  |
Nonaccrual Loans Receivable | 26,000 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 0 us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember |
Average investment in impaired loans | 11,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 12,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember
Balance of impaired loans | 26,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember
Recorded Investment | 26,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember
Unpaid Principal Balance | 28,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember
Related Allowance | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember
Average Recorded Investment | 11,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 12,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember
Recognized Interest Income | 3,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember
Consumer | With an Allowance Recorded |  |  |
Nonaccrual Loans [Abstract] |  |  |
Average investment in impaired loans | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 9,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Balance of impaired loans | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Recorded Investment | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Unpaid Principal Balance | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Related Allowance | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Average Recorded Investment | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 9,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Recognized Interest Income | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithAllowanceRecordedMember
Consumer | With No Related Allowance Recorded |  |  |
Nonaccrual Loans [Abstract] |  |  |
Average investment in impaired loans | 11,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 3,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Balance of impaired loans | 26,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Recorded Investment | 26,000 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Unpaid Principal Balance | 28,000 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Related Allowance | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableRelatedAllowance / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Average Recorded Investment | 11,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 0 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | 3,000 us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Recognized Interest Income | $ 3,000 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | $ 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember | $ 0 us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_ConsumerLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = fnlc_WithNoRelatedAllowanceRecordedMember
Loans Receivable in Bankruptcy |  |  |
Nonaccrual Loans [Abstract] |  |  |
Financing Receivable, Number of Loans | 9 fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = us-gaap_LoansReceivableMember |  |

X
- Details
Name: | fnlc_CompositionOfLoanPortfolioAbstract
Namespace Prefix: | fnlc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- 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
Name: | fnlc_FinancingReceivableLoansClassifiedAsTroubledDebtRestructuringsThatAreInvolvedInBankruptcy
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Carrying amount of loans classified as troubled debt restructurings that had been placed on TDR status in previous 12 months. + References No definition available. + Details
Name: | fnlc_FinancingReceivableLoansClassifiedasTroubledDebtRestructuringsThatHadBeenPlacedonTDRStatusinPrevious12Months
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- 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
Name: | fnlc_FinancingReceivableLoansClassifiedAsTroubledDebtRestructuringsThatWereOnNonAccrualStatus
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The number of financing receivables that have been modified by troubled debt restructurings during the current period. + References No definition available. + Details
Name: | fnlc_FinancingReceivableModificationsNumberOfContractsDuringPeriod
Namespace Prefix: | fnlc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of financing receivables greater than 30 days past due that have been modified by troubled debt restructurings and that have been placed in the TDR status in the previous 12 months. + References No definition available. + Details
Name: | fnlc_FinancingReceivableModificationsNumberOfContractsGreaterThan30DaysPastDuePlaceInTDRInPrevious12Months
Namespace Prefix: | fnlc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition 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. + References No definition available. + Details
Name: | fnlc_FinancingReceivableModificationsPreModificationRecordedInvestmentDuringPeriod
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The number of loans classified as troubled debt restructurings that were on non-accrual status as of the balance sheet date. + References No definition available. + Details
Name: | fnlc_FinancingReceivableNumberOfLoansClassifiedAsTroubledDebtRestructuringsThatWereOnNonAccrualStatus
Namespace Prefix: | fnlc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Financing receivables that are greater than 30 days past due. + References No definition available. + Details
Name: | fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDue
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Financing receivables that are greater than 30 days past due and that had been placed in TDR status in the previous 12 months. + References No definition available. + Details
Name: | fnlc_FinancingReceivableRecordedInvestmentGreaterThan30DaysPastDuePlacedInTDRInPrevious12Months
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Financing Receivable, Recorded Investment, Greater than 30 Days Past Due, Placed in T D R in Previous 12 months, Specific Allowance during Period + References No definition available. + Details
Name: | fnlc_FinancingReceivableRecordedInvestmentGreaterthan30DaysPastDuePlacedinTDRinPrevious12monthsSpecificAllowanceduringPeriod
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Portion of loans receivable balance which has an offsetting allowance for doubtful accounts. + References No definition available. + Details
Name: | fnlc_ImpairedFinancingReceivableWithAllowance
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The portion of loans receivable balance which doesn't have an offsetting allowance for doubtful accounts. + References No definition available. + Details
Name: | fnlc_ImpairedFinancingReceivableWithNoAllowance
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Loans and Leases Receivables, Related Parties, Additions, Aggregated Over 60,000 Dollars + References No definition available. + Details
Name: | fnlc_LoansandLeasesReceivablesRelatedPartiesAdditionsAggregatedOver60000Dollars
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Loans and Leases Receivables, Related Parties, Collections, Aggregated Over 60,000 Dollars + References No definition available. + Details
Name: | fnlc_LoansandLeasesReceivablesRelatedPartiesCollectionsAggregatedOver60000Dollars
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Loans classified as troubled debt restructurings that are involved in foreclosure as of the balance sheet date. + References No definition available. + Details
Name: | fnlc_LoansClassifiedAsTroubledDebtRestructuringsThatAreInvolvedInForeclosure
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Financing receivables that are less than 60 days past due but more than 29 days past due. + References No definition available. + Details
Name: | fnlc_LoansReceivable3059DaysPastDue
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Financing receivables that are more than 59 days past due and less than 90 days past due. + References No definition available. + Details
Name: | fnlc_LoansReceivable6089DaysPastDue
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The number of loans classified as troubled debt restructurings that are involved in foreclosure as of the balance sheet date. + References No definition available. + Details
Name: | fnlc_NumberOfLoansClassifiedAsTroubledDebtRestructuringsThatAreInvolvedInForeclosure
Namespace Prefix: | fnlc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition 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. + References No definition available. + Details
Name: | fnlc_PercentageOfLoansReceivableByType
Namespace Prefix: | fnlc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition 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. + References No definition available. + Details
Name: | fnlc_RelatedPartyLoanReceivableAggregatedOver60000Dollars
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Specific allowance for loan and lease losses on receivable financings that are classified as troubled debt restructurings during the current period. + References No definition available. + Details
Name: | fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceCurrentPeriod
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Specific allowance for loan and lease losses on receivable financings that are classified as troubled debt restructurings during the period. + References No definition available. + Details
Name: | fnlc_TroubledDebtRestructuringLoansAndLeasesReceivableSpecificAllowanceDuringPeriod
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition For an unclassified balance sheet, amounts due from related parties including affiliates, employees, joint ventures, officers and stockholders, immediate families thereof, and pension funds. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(k)(1)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 3 -Article 7 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.3) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.10(3)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_DueFromRelatedParties
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of the collateral pledged in support of federal home loan bank advances outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823 + Details
Name: | us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=28368275&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Post-modification amount of investment in financing receivables modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=28368275&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Pre-modification amount of investment in financing receivables modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=28368275&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=25495931&loc=d3e18845-111554 + Details
Name: | us-gaap_FinancingReceivableModificationsRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 34 -URI http://asc.fasb.org/extlink&oid=28368275&loc=SL6953682-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Recorded investment in financing receivables that are 90 days or more past due and still accruing. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5111-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentAgingAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Financing receivables that are current. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7A -URI http://asc.fasb.org/extlink&oid=28368275&loc=SL6953401-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Financing receivables that are equal to or greater than 90 days past due. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7A -URI http://asc.fasb.org/extlink&oid=28368275&loc=SL6953401-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5111-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Recorded Investment in financing receivables that are past due at the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7A -URI http://asc.fasb.org/extlink&oid=28368275&loc=SL6953401-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentPastDue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5212-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5258-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(3) -URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableInterestIncomeCashBasisMethod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 14A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=28368275&loc=SL6953550-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of allowance for credit losses related to recorded investment. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableRelatedAllowance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (a)(4) -URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5212-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_LoanAndLeaseReceivablesImpairedAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5074-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 20 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6378556&loc=d3e10152-111534 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 30 -Section 50 -Paragraph 4 -Subparagraph (a)(4) -URI http://asc.fasb.org/extlink&oid=25496975&loc=d3e45377-112738 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Article 9 + Details
Name: | us-gaap_LoansAndLeasesReceivableDeferredIncome
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition 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). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=25495931&loc=d3e18794-111554 + Details
Name: | us-gaap_LoansAndLeasesReceivableImpairedInterestLostOnNonaccrualLoans
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5074-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522 + Details
Name: | us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_LoansAndLeasesReceivableRelatedPartiesRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5086-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6467456&loc=d3e113888-111728 + Details
Name: | us-gaap_LoansPledgedAsCollateral
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_LoansReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=fnlc_CommercialConstructionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=fnlc_CommercialOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=fnlc_MunicipalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=fnlc_ResidentialConstructionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=fnlc_ResidentialTermMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialRealEstateOtherReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConsumerLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableTroubledDebtRestructuringAxis=fnlc_MunicipalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableTroubledDebtRestructuringAxis=fnlc_ResidentialConstructionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableTroubledDebtRestructuringAxis=fnlc_ResidentialTermMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableTroubledDebtRestructuringAxis=fnlc_WithAllowanceRecordedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableTroubledDebtRestructuringAxis=fnlc_WithNoRelatedAllowanceRecordedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableTroubledDebtRestructuringAxis=us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableTroubledDebtRestructuringAxis=us-gaap_CommercialRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableTroubledDebtRestructuringAxis=us-gaap_CommercialRealEstateOtherReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableTroubledDebtRestructuringAxis=us-gaap_ConsumerLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableTroubledDebtRestructuringAxis=us-gaap_HomeEquityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |