XML 51 R40.htm IDEA: XBRL DOCUMENT
v3.21.2

Investment Securities - Narrative (Details) | 9 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | ---
Sep. 30, 2021 USD ($) security state | Sep. 30, 2020 USD ($) security | Dec. 31, 2020 USD ($) security | Jun. 30, 2020 security | Sep. 30, 2014 USD ($)
Debt Securities, Available-for-sale [Line Items] |  |  |  |  |
Number of securities temporarily impaired (security) | security | 184 | 75 | 50 |  |
Number of securities temporarily impaired for twelve months or more (security) | security | 19 | 10 | 10 |  |
Period of temporary impairment | 12 months | 12 months | 12 months |  |
Amortized cost of securities transferred |  |  |  |  | $ 89,780,000
Fair value of securities transferred |  |  |  |  | 89,757,000
Net unrealized loss, net of taxes on transferred securities |  |  |  |  | $ 15,000
Unamortized balance of net unrealized losses transferred | $ 99,000 | $ 139,000 | $ 133,000 |  |
Number of states | state | 6 |  |  |  |
FHLB stock investment | $ 7,802,000 | 9,508,000 | 9,508,000 |  |
Impairment losses | 0 |  |  |  |
State and political subdivisions |  |  |  |  |
Debt Securities, Available-for-sale [Line Items] |  |  |  |  |
Number of securities temporarily impaired (security) | security |  |  |  | 28 |
Proceeds from sales of municipal securities | 8,600,000 |  |  |  |
Cumulative book value | 8,332,000 |  |  |  |
Net realized gain from sale of municipal securities | 268,000 |  |  |  |
Other equity securities |  |  |  |  |
Debt Securities, Available-for-sale [Line Items] |  |  |  |  |
Securities pledged as collateral | $ 349,978,000 | $ 285,253,000 | $ 297,326,000 |  |

X
- Definition Available-for-Sale Securities, Transferred Security, at Carrying Value + References No definition available. + Details
Name: | fnlc_AvailableforSaleSecuritiesTransferredSecurityatCarryingValue
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Available-for-Sale, Transferred Security, at Fair Value + References No definition available. + Details
Name: | fnlc_AvailableforSaleSecuritiesTransferredSecurityatFairValue
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Available-for-sale Securities, Transferred to Held-to-maturity Securities, Accumulated Unrealized Gain (Loss) + References No definition available. + Details
Name: | fnlc_AvailableforsaleSecuritiesTransferredtoHeldtomaturitySecuritiesAccumulatedUnrealizedGainLoss
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Length of time securities are temporarily impaired. + References No definition available. + Details
Name: | fnlc_LengthOfTimeSecuritiesTemporarilyImpaired
Namespace Prefix: | fnlc_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of securities with unrealized losses, classified as temporarily impaired, held in a Company's portfolio as of the balance sheet date. + References No definition available. + Details
Name: | fnlc_NumberOfSecuritiesTemporarilyImpaired
Namespace Prefix: | fnlc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of securities temporarily impaired as of the balance sheet date for a period of 12 months or more. + References No definition available. + Details
Name: | fnlc_NumberOfSecuritiesTemporarilyImpairedTwelveMonths
Namespace Prefix: | fnlc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of States in New England where Federal Home Loan Bank do housing and financing services. + References No definition available. + Details
Name: | fnlc_NumberOfStatesInNewEnglandWhereFhlbServe
Namespace Prefix: | fnlc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Other Comprehensive Income (Loss), Accumulated Unrealized Gain (Loss) on Transfer of Available-for-sale Securities to Held-to-maturity + References No definition available. + Details
Name: | fnlc_OtherComprehensiveIncomeLossAccumulatedUnrealizedGainLossonTransferofAvailableforsaleSecuritiestoHeldtomaturity
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition As of the balance sheet date, the excess of carrying value (amortized cost) over fair value of a security categorized as non marketable securities, exclusive of dividend or interest income recognized but not yet received and exclusive of any write-downs for other-than-temporary impairment. Such item represents the gross unrecognized holding loss. + References No definition available. + Details
Name: | fnlc_RestrictedEquitySecuritiesUnrealizedLosses
Namespace Prefix: | fnlc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of restricted investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 954 -SubTopic 210 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=120413173&loc=SL6242262-115580 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 30 -Section 50 -Paragraph 1A -Subparagraph (b)(1)(i) -URI http://asc.fasb.org/extlink&oid=109249958&loc=SL6224234-111729 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 954 -SubTopic 210 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=120413209&loc=SL6242269-115581 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleRestricted
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity), sold. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27405-111563 + Details
Name: | us-gaap_DebtSecuritiesHeldToMaturitySoldAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 325 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=123599499&loc=d3e63345-112809 + Details
Name: | us-gaap_FederalHomeLoanBankStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of gain (loss) on sale of investment in debt security measured at amortized cost (held-to-maturity), including other-than-temporary impairment (OTTI). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27405-111563 + Details
Name: | us-gaap_HeldToMaturitySecuritiesSoldSecurityRealizedGainLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The cash inflow associated with the sale of securities that had been designated as held-to-maturity. Excludes proceeds from maturities, prepayments and calls by the issuer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=124260329&loc=d3e26853-111562 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3179-108585 + Details
Name: | us-gaap_ProceedsFromSaleOfHeldToMaturitySecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CollateralAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |