XML 52 R41.htm IDEA: XBRL DOCUMENT
v3.19.2

Investment Securities - Additional Information (Details) $ in Thousands | 6 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Jun. 30, 2019 USD ($) security state | Jun. 30, 2018 USD ($) security | Dec. 31, 2018 USD ($) security | Sep. 30, 2014 USD ($)
Investment [Line Items] |  |  |  |
Number of securities temporarily impaired (security) | security | 133 | 480 | 511 |
Number of securities temporarily impaired for twelve months or more (security) | security | 127 | 160 | 232 |
Length of time securities temporarily impaired (months) | 12 months | 12 months | 12 months |
Amortized cost of transferred securities from available-for-sale to held-to-maturity |  |  |  | $ 89,780
Fair value of transferred securities from available-for-sale to held-to-maturity |  |  |  | 89,757
Net unrealized loss, net of taxes on transferred securities |  |  |  | $ 15
Unamortized balance of net unrealized losses | $ 190 | $ 189 | $ 197 |
Number of states in New England where FHLB serve (state) | state | 6 |  |  |
Federal Home Loan Bank Stock | $ 7,945 | 11,326 | 10,549 |
Other equity securities |  |  |  |
Investment [Line Items] |  |  |  |
Fair value of securities pledged as collateral | $ 190,725 | $ 203,196 | $ 222,829 |
State and political subdivisions |  |  |  |
Investment [Line Items] |  |  |  |
Percentage of overall security holdings downgraded | 0.40% |  |  |

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 Debt Securities, Available-for-sale, Downgraded, Percent + References No definition available. + Details
Name: | fnlc_DebtSecuritiesAvailableforsaleDowngradedPercent
Namespace Prefix: | fnlc_
Data Type: | num:percentItemType
Balance Type: | na
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
- References No definition available. + Details
Name: | invest_InvestmentLineItems
Namespace Prefix: | invest_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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 860 -SubTopic 30 -Section 50 -Paragraph 1A -Subparagraph (b)(1)(i) -URI http://asc.fasb.org/extlink&oid=109249958&loc=SL6224234-111729 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleRestricted
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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=75031641&loc=d3e63345-112809 + Details
Name: | us-gaap_FederalHomeLoanBankStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

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