XML 76 R62.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Summary of Significant Accounting Policies (Details) | 12 Months Ended
--- | ---
Dec. 31, 2024 USD ($) office
Accounting Policies [Abstract] |
Number of offices | office | 18
Goodwill and intangible asset impairment | $ | $ 0
Mortgage loan outstanding percentage | 0.25%

X
- Definition Mortgage Servicing Rights, Fee, Percentage + References No definition available. + Details
Name: | fnlc_MortgageServicingRightsFeePercentage
Namespace Prefix: | fnlc_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number Of Offices + References No definition available. + Details
Name: | fnlc_NumberOfOffices
Namespace Prefix: | fnlc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_AccountingPoliciesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total loss recognized during the period from the impairment of goodwill plus the loss recognized in the period resulting from the impairment of the carrying amount of intangible assets, other than goodwill. + References No definition available. + Details
Name: | us-gaap_GoodwillAndIntangibleAssetImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration