XML 28 R52.htm IDEA: XBRL DOCUMENT v2.4.1.9
Allowance for Loan Losses - Risk Ratings by Segment (Details) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Mar. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable $ 418,436fnlc_CommercialAndMunicipalRiskRatedLoansReceivable $ 398,198fnlc_CommercialAndMunicipalRiskRatedLoansReceivable $ 376,939fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
Commercial real estate      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 242,021fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember		 242,311fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember		 240,187fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
Commercial construction      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 34,683fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember		 30,932fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember		 21,686fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
Commercial other      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 115,455fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember		 104,531fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember		 97,276fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
Municipal      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 26,277fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember		 20,424fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember		 17,790fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
1 Strong      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 355fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Strong1Member		 342fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Strong1Member		 276fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Strong1Member
1 Strong | Commercial real estate      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 11fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Strong1Member		 12fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Strong1Member		 15fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Strong1Member
1 Strong | Commercial construction      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Strong1Member		 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Strong1Member		 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Strong1Member
1 Strong | Commercial other      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 344fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Strong1Member		 330fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Strong1Member		 261fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Strong1Member
1 Strong | Municipal      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Strong1Member		 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Strong1Member		 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Strong1Member
2 Above Average      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 45,334fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_AboveAverage2Member		 39,438fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_AboveAverage2Member		 33,444fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_AboveAverage2Member
2 Above Average | Commercial real estate      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 11,599fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_AboveAverage2Member		 12,668fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_AboveAverage2Member		 9,287fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_AboveAverage2Member
2 Above Average | Commercial construction      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 766fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_AboveAverage2Member		 771fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_AboveAverage2Member		 773fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_AboveAverage2Member
2 Above Average | Commercial other      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 8,282fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_AboveAverage2Member		 7,210fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_AboveAverage2Member		 7,458fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_AboveAverage2Member
2 Above Average | Municipal      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 24,687fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_AboveAverage2Member		 18,789fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_AboveAverage2Member		 15,926fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_AboveAverage2Member
3 Satisfactory      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 81,403fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Satisfactory3Member		 78,125fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Satisfactory3Member		 64,726fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Satisfactory3Member
3 Satisfactory | Commercial real estate      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 52,828fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Satisfactory3Member		 50,275fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Satisfactory3Member		 44,918fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Satisfactory3Member
3 Satisfactory | Commercial construction      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 2,227fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Satisfactory3Member		 1,983fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Satisfactory3Member		 1,080fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Satisfactory3Member
3 Satisfactory | Commercial other      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 24,758fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Satisfactory3Member		 24,232fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Satisfactory3Member		 16,864fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Satisfactory3Member
3 Satisfactory | Municipal      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 1,590fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Satisfactory3Member		 1,635fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Satisfactory3Member		 1,864fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Satisfactory3Member
4 Average      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 189,467fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Average4Member		 176,959fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Average4Member		 165,196fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Average4Member
4 Average | Commercial real estate      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 108,480fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Average4Member		 108,719fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Average4Member		 102,361fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Average4Member
4 Average | Commercial construction      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 25,867fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Average4Member		 23,345fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Average4Member		 16,388fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Average4Member
4 Average | Commercial other      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 55,120fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Average4Member		 44,895fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Average4Member		 46,447fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Average4Member
4 Average | Municipal      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Average4Member		 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Average4Member		 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Average4Member
5 Watch      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 57,025fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Watch5Member		 56,712fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Watch5Member		 43,907fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Watch5Member
5 Watch | Commercial real estate      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 36,816fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Watch5Member		 36,974fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Watch5Member		 33,079fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Watch5Member
5 Watch | Commercial construction      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 2,567fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Watch5Member		 1,567fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Watch5Member		 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Watch5Member
5 Watch | Commercial other      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 17,642fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Watch5Member		 18,171fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Watch5Member		 10,828fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Watch5Member
5 Watch | Municipal      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Watch5Member		 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Watch5Member		 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Watch5Member
6 OAEM      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 13,848fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Oaem6Member		 14,335fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Oaem6Member		 33,502fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Oaem6Member
6 OAEM | Commercial real estate      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 9,670fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Oaem6Member		 9,846fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Oaem6Member		 26,951fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Oaem6Member
6 OAEM | Commercial construction      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 2,509fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Oaem6Member		 2,519fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Oaem6Member		 2,668fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Oaem6Member
6 OAEM | Commercial other      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 1,669fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Oaem6Member		 1,970fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Oaem6Member		 3,883fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Oaem6Member
6 OAEM | Municipal      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Oaem6Member		 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Oaem6Member		 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= fnlc_Oaem6Member
7 Substandard      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 31,004fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember		 32,287fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember		 35,848fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember
7 Substandard | Commercial real estate      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 22,617fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember		 23,817fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember		 23,576fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember
7 Substandard | Commercial construction      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 747fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember		 747fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember		 777fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember
7 Substandard | Commercial other      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 7,640fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember		 7,723fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember		 11,495fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember
7 Substandard | Municipal      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember		 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember		 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember
8 Doubtful      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember		 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember		 40fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember
8 Doubtful | Commercial real estate      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember		 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember		 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstatePortfolioSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember
8 Doubtful | Commercial construction      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember		 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember		 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialConstructionMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember
8 Doubtful | Commercial other      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember		 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember		 40fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_CommercialOtherMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember
8 Doubtful | Municipal      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Commercial and municipal risk-rated loans receivable $ 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember		 $ 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember		 $ 0fnlc_CommercialAndMunicipalRiskRatedLoansReceivable
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fnlc_MunicipalMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember