| **Earnings Per Share  - Schedule of Options and Warrants Outstanding (Details)** | Jun. 30, 2014 | Dec. 31, 2013 | Jun. 30, 2013 |
|----------------------------------------------------------------------------------|---------------|---------------|---------------|
| **Schedule of Outstanding Options And Warrants [Line Items]**                    |          |          |          |
| Incentive stock options (in shares)                                              | 42,000        | 42,000        | 42,000        |
| Warrants issued to U.S. Treasury (in shares)                                     | 225,904       |          | 225,904       |
| Total dilutive securities (in shares)                                            | 267,904       |          | 267,904       |
| In-the-Money [Member]                                                            |          |          |          |
| **Schedule of Outstanding Options And Warrants [Line Items]**                    |          |          |          |
| Incentive stock options (in shares)                                              | 0             |          | 0             |
| Warrants issued to U.S. Treasury (in shares)                                     | 0             |          | 225,904       |
| Total dilutive securities (in shares)                                            | 0             |          | 225,904       |
| Out-of-the-Money [Member]                                                        |          |          |          |
| **Schedule of Outstanding Options And Warrants [Line Items]**                    |          |          |          |
| Incentive stock options (in shares)                                              | 42,000        |          | 42,000        |
| Warrants issued to U.S. Treasury (in shares)                                     | 225,904       |          | 0             |
| Total dilutive securities (in shares)                                            | 267,904       |          | 42,000        |

| X                                                                                                                                                                                                                                                                                                                                                          |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The total number of shares reserved for issuance under stock option and warrants and are outstanding as of the balance sheet date.
+ References
No definition available.
+ Details**Name:**fnlc_EarningsPerShareTotalDilutiveSecurities**Namespace Prefix:**fnlc_**Data Type:**xbrli:sharesItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                              |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**fnlc_ScheduleOfOutstandingOptionsAndWarrantsLineItems**Namespace Prefix:**fnlc_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.
+ 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.(i)(2)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph i -Subparagraph 2 -Article 4
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of options outstanding, including both vested and non-vested options.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901
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