| **Fair Value - Assets and Liabilities at Fair Value (Details) - USD ($) $ in Thousands**         | Jun. 30, 2016 | Dec. 31, 2015 | Jun. 30, 2015 | Dec. 31, 2014 |
|--------------------------------------------------------------------------------------------------|---------------|---------------|---------------|---------------|
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Cash and cash equivalents                                                                        | $ 20,838      | $ 14,299      | $ 16,481      | $ 13,057      |
| Interest bearing deposits in other banks                                                         | 7,568         | 4,013         | 24,565        |          |
| Securities available for sale                                                                    | 241,327       | 223,039       | 213,814       |          |
| Securities to be held to maturity                                                                | 216,272       | 240,023       | 249,250       |          |
| Securities to be held to maturity                                                                | 225,200       | 243,123       | 248,698       |          |
| Restricted equity securities                                                                     | 14,441        | 14,257        | 13,912        |          |
| Loans held for sale                                                                              | 1,553         | 349           | 0             |          |
| Mortgage servicing rights                                                                        | 1,489         | 1,915         | 1,914         |          |
| Demand deposits                                                                                  | 130,168       | 130,566       | 107,244       |          |
| NOW deposits                                                                                     | 254,136       | 242,638       | 221,964       |          |
| Money market deposits                                                                            | 73,030        | 92,994        | 102,219       |          |
| Savings deposits                                                                                 | 208,826       | 206,009       | 186,777       |          |
| Total deposits                                                                                   | 1,145,709     | 1,043,189     | 1,096,323     |          |
| Carrying value                                                                                   |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Cash and cash equivalents                                                                        | 20,838        | 14,299        | 16,481        |          |
| Interest bearing deposits in other banks                                                         | 7,568         | 4,013         | 24,565        |          |
| Securities available for sale                                                                    | 241,327       | 223,039       | 213,814       |          |
| Securities to be held to maturity                                                                | 216,272       | 240,023       | 249,250       |          |
| Restricted equity securities                                                                     | 14,441        | 14,257        | 13,912        |          |
| Loans held for sale                                                                              | 1,553         | 349           |          |          |
| Loans                                                                                            | 1,028,015     | 978,722       | 953,201       |          |
| Mortgage servicing rights                                                                        | 948           | 1,093         | 1,071         |          |
| Accrued interest receivable                                                                      | 6,372         | 4,912         | 6,180         |          |
| Demand deposits                                                                                  | 130,168       | 130,566       | 107,244       |          |
| NOW deposits                                                                                     | 254,136       | 242,638       | 221,964       |          |
| Money market deposits                                                                            | 73,030        | 92,994        | 102,219       |          |
| Savings deposits                                                                                 | 208,826       | 206,009       | 186,777       |          |
| Local certificates of deposit                                                                    | 211,006       | 201,420       | 194,653       |          |
| National certificates of deposit                                                                 | 268,543       | 169,562       | 283,466       |          |
| Total deposits                                                                                   | 1,145,709     | 1,043,189     | 1,096,323     |          |
| Repurchase agreements                                                                            | 82,965        | 87,103        | 87,875        |          |
| Federal Home Loan Bank advances                                                                  | 200,130       | 250,354       | 190,138       |          |
| Total borrowed funds                                                                             | 283,095       | 337,457       | 278,013       |          |
| Interest rate swap agreements                                                                    | 208           |          |          |          |
| Accrued interest payable                                                                         | 499           | 435           | 506           |          |
| Carrying value | Commercial real estate                                                          |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 298,822       | 265,616       | 245,788       |          |
| Carrying value | Commercial construction                                                         |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 18,078        | 24,166        | 38,636        |          |
| Carrying value | Commercial other                                                                |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 134,632       | 126,551       | 126,191       |          |
| Carrying value | Municipal                                                                       |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 25,512        | 19,730        | 22,801        |          |
| Carrying value | Residential term                                                                |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 401,911       | 401,315       | 376,632       |          |
| Carrying value | Residential construction                                                        |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 13,364        | 8,421         | 14,182        |          |
| Carrying value | Home equity line of credit                                                      |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 111,537       | 109,101       | 107,657       |          |
| Carrying value | Consumer                                                                        |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 24,159        | 23,822        | 21,314        |          |
| Total Fair Value                                                                                 |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Cash and cash equivalents                                                                        | 20,838        | 14,299        | 16,481        |          |
| Interest bearing deposits in other banks                                                         | 7,568         | 4,013         | 24,565        |          |
| Securities available for sale                                                                    | 241,327       | 223,039       | 213,814       |          |
| Securities to be held to maturity                                                                | 225,200       | 243,123       | 248,698       |          |
| Restricted equity securities                                                                     | 14,441        | 14,257        | 13,912        |          |
| Loans held for sale                                                                              | 1,553         | 349           |          |          |
| Loans                                                                                            | 1,032,533     | 978,707       | 955,709       |          |
| Mortgage servicing rights                                                                        | 1,489         | 1,915         | 1,914         |          |
| Accrued interest receivable                                                                      | 6,372         | 4,912         | 6,180         |          |
| Demand deposits                                                                                  | 134,043       | 125,651       | 102,223       |          |
| NOW deposits                                                                                     | 253,251       | 224,627       | 202,972       |          |
| Money market deposits                                                                            | 68,204        | 82,050        | 89,208        |          |
| Savings deposits                                                                                 | 196,812       | 181,010       | 162,469       |          |
| Local certificates of deposit                                                                    | 213,726       | 201,013       | 194,877       |          |
| National certificates of deposit                                                                 | 268,873       | 169,617       | 283,514       |          |
| Total deposits                                                                                   | 1,134,909     | 983,968       | 1,035,263     |          |
| Repurchase agreements                                                                            | 81,775        | 82,168        | 82,365        |          |
| Federal Home Loan Bank advances                                                                  | 202,184       | 250,027       | 192,471       |          |
| Total borrowed funds                                                                             | 283,959       | 332,195       | 274,836       |          |
| Interest rate swap agreements                                                                    | 208           |          |          |          |
| Accrued interest payable                                                                         | 499           | 435           | 506           |          |
| Total Fair Value | Commercial real estate                                                        |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 294,749       | 262,763       | 243,426       |          |
| Total Fair Value | Commercial construction                                                       |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 17,832        | 23,906        | 38,265        |          |
| Total Fair Value | Commercial other                                                              |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 134,567       | 126,141       | 126,149       |          |
| Total Fair Value | Municipal                                                                     |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 26,833        | 20,331        | 23,092        |          |
| Total Fair Value | Residential term                                                              |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 410,502       | 405,315       | 382,268       |          |
| Total Fair Value | Residential construction                                                      |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 13,289        | 8,379         | 14,150        |          |
| Total Fair Value | Home equity line of credit                                                    |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 110,635       | 108,118       | 106,966       |          |
| Total Fair Value | Consumer                                                                      |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 24,126        | 23,754        | 21,393        |          |
| Total Fair Value | Level 1                                                                       |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Cash and cash equivalents                                                                        | 20,838        | 14,299        | 16,481        |          |
| Interest bearing deposits in other banks                                                         | 7,568         | 4,013         | 24,565        |          |
| Securities available for sale                                                                    | 0             | 0             | 0             |          |
| Securities to be held to maturity                                                                | 0             | 0             | 0             |          |
| Restricted equity securities                                                                     | 0             | 0             | 0             |          |
| Loans held for sale                                                                              | 0             | 0             |          |          |
| Loans                                                                                            | 0             | 0             | 0             |          |
| Mortgage servicing rights                                                                        | 0             | 0             | 0             |          |
| Accrued interest receivable                                                                      | 0             | 0             | 0             |          |
| Demand deposits                                                                                  | 0             | 0             | 0             |          |
| NOW deposits                                                                                     | 0             | 0             | 0             |          |
| Money market deposits                                                                            | 0             | 0             | 0             |          |
| Savings deposits                                                                                 | 0             | 0             | 0             |          |
| Local certificates of deposit                                                                    | 0             | 0             | 0             |          |
| National certificates of deposit                                                                 | 0             | 0             | 0             |          |
| Total deposits                                                                                   | 0             | 0             | 0             |          |
| Repurchase agreements                                                                            | 0             | 0             | 0             |          |
| Federal Home Loan Bank advances                                                                  | 0             | 0             | 0             |          |
| Total borrowed funds                                                                             | 0             | 0             | 0             |          |
| Interest rate swap agreements                                                                    | 0             |          |          |          |
| Accrued interest payable                                                                         | 0             | 0             | 0             |          |
| Total Fair Value | Level 1 | Commercial real estate                                              |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 0             | 0             | 0             |          |
| Total Fair Value | Level 1 | Commercial construction                                             |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 0             | 0             | 0             |          |
| Total Fair Value | Level 1 | Commercial other                                                    |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 0             | 0             | 0             |          |
| Total Fair Value | Level 1 | Municipal                                                           |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 0             | 0             | 0             |          |
| Total Fair Value | Level 1 | Residential term                                                    |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 0             | 0             | 0             |          |
| Total Fair Value | Level 1 | Residential construction                                            |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 0             | 0             | 0             |          |
| Total Fair Value | Level 1 | Home equity line of credit                                          |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 0             | 0             | 0             |          |
| Total Fair Value | Level 1 | Consumer                                                            |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 0             | 0             | 0             |          |
| Total Fair Value | Level 2                                                                       |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Cash and cash equivalents                                                                        | 0             | 0             | 0             |          |
| Interest bearing deposits in other banks                                                         | 0             | 0             | 0             |          |
| Securities available for sale                                                                    | 241,327       | 223,039       | 213,814       |          |
| Securities to be held to maturity                                                                | 225,200       | 243,123       | 248,698       |          |
| Restricted equity securities                                                                     | 14,441        | 14,257        | 13,912        |          |
| Loans held for sale                                                                              | 1,553         | 349           |          |          |
| Loans                                                                                            | 1,889         | 699           | 1,830         |          |
| Mortgage servicing rights                                                                        | 1,489         | 1,915         | 1,914         |          |
| Accrued interest receivable                                                                      | 6,372         | 4,912         | 6,180         |          |
| Demand deposits                                                                                  | 134,043       | 125,651       | 102,223       |          |
| NOW deposits                                                                                     | 253,251       | 224,627       | 202,972       |          |
| Money market deposits                                                                            | 68,204        | 82,050        | 89,208        |          |
| Savings deposits                                                                                 | 196,812       | 181,010       | 162,469       |          |
| Local certificates of deposit                                                                    | 213,726       | 201,013       | 194,877       |          |
| National certificates of deposit                                                                 | 268,873       | 169,617       | 283,514       |          |
| Total deposits                                                                                   | 1,134,909     | 983,968       | 1,035,263     |          |
| Repurchase agreements                                                                            | 81,775        | 82,168        | 82,365        |          |
| Federal Home Loan Bank advances                                                                  | 202,184       | 250,027       | 192,471       |          |
| Total borrowed funds                                                                             | 283,959       | 332,195       | 274,836       |          |
| Interest rate swap agreements                                                                    | 208           |          |          |          |
| Accrued interest payable                                                                         | 499           | 435           | 506           |          |
| Total Fair Value | Level 2 | Commercial real estate                                              |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 544           | 0             | 170           |          |
| Total Fair Value | Level 2 | Commercial construction                                             |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 0             | 0             | 0             |          |
| Total Fair Value | Level 2 | Commercial other                                                    |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 348           | 0             | 25            |          |
| Total Fair Value | Level 2 | Municipal                                                           |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 0             | 0             | 0             |          |
| Total Fair Value | Level 2 | Residential term                                                    |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 933           | 0             | 1,635         |          |
| Total Fair Value | Level 2 | Residential construction                                            |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 0             | 0             | 0             |          |
| Total Fair Value | Level 2 | Home equity line of credit                                          |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 0             | 699           | 0             |          |
| Total Fair Value | Level 2 | Consumer                                                            |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 64            | 0             | 0             |          |
| Total Fair Value | Level 3                                                                       |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Cash and cash equivalents                                                                        | 0             | 0             | 0             |          |
| Interest bearing deposits in other banks                                                         | 0             | 0             | 0             |          |
| Securities available for sale                                                                    | 0             | 0             | 0             |          |
| Securities to be held to maturity                                                                | 0             | 0             | 0             |          |
| Restricted equity securities                                                                     | 0             | 0             | 0             |          |
| Loans held for sale                                                                              | 0             | 0             |          |          |
| Loans                                                                                            | 1,030,644     | 978,008       | 953,879       |          |
| Mortgage servicing rights                                                                        | 0             | 0             | 0             |          |
| Accrued interest receivable                                                                      | 0             | 0             | 0             |          |
| Demand deposits                                                                                  | 0             | 0             | 0             |          |
| NOW deposits                                                                                     | 0             | 0             | 0             |          |
| Money market deposits                                                                            | 0             | 0             | 0             |          |
| Savings deposits                                                                                 | 0             | 0             | 0             |          |
| Local certificates of deposit                                                                    | 0             | 0             | 0             |          |
| National certificates of deposit                                                                 | 0             | 0             | 0             |          |
| Total deposits                                                                                   | 0             | 0             | 0             |          |
| Repurchase agreements                                                                            | 0             | 0             | 0             |          |
| Federal Home Loan Bank advances                                                                  | 0             | 0             | 0             |          |
| Total borrowed funds                                                                             | 0             | 0             | 0             |          |
| Interest rate swap agreements                                                                    | 0             |          |          |          |
| Accrued interest payable                                                                         | 0             | 0             | 0             |          |
| Total Fair Value | Level 3 | Commercial real estate                                              |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 294,205       | 262,763       | 243,256       |          |
| Total Fair Value | Level 3 | Commercial construction                                             |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 17,832        | 23,906        | 38,265        |          |
| Total Fair Value | Level 3 | Commercial other                                                    |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 134,219       | 126,141       | 126,124       |          |
| Total Fair Value | Level 3 | Municipal                                                           |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 26,833        | 20,331        | 23,092        |          |
| Total Fair Value | Level 3 | Residential term                                                    |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 409,569       | 405,315       | 380,633       |          |
| Total Fair Value | Level 3 | Residential construction                                            |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 13,289        | 8,379         | 14,150        |          |
| Total Fair Value | Level 3 | Home equity line of credit                                          |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | 110,635       | 107,419       | 106,966       |          |
| Total Fair Value | Level 3 | Consumer                                                            |          |          |          |          |
| **Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]** |          |          |          |          |
| Loans                                                                                            | $ 24,062      | $ 23,754      | $ 21,393      |          |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Represents the portion of the balance sheet assertion valued at fair value whether such amount is presented as a separate caption or as a parenthetical disclosure. Element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. May be used in both the balance sheet and disclosure in the same submission. This item represents the amount shown on an entity's books for accrued interest receivable.
+ References
No definition available.
+ Details**Name:**fnlc_AccruedInterestReceivableFairValueDisclosure**Namespace Prefix:**fnlc_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                   |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The aggregate amount of local time deposits, including certificates of deposits, individual retirement accounts and open accounts.
+ References
No definition available.
+ Details**Name:**fnlc_LocalCertificatesofDeposit**Namespace Prefix:**fnlc_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                         |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The aggregate amount of national time deposits, including certificates of deposits, individual retirement accounts and open accounts.
+ References
No definition available.
+ Details**Name:**fnlc_NationalCertificatesOfDeposit**Namespace Prefix:**fnlc_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of stock held at Federal Home Loan Bank and Federal Reserve Bank. Federal Home Loan Bank (FHLB) stock and Federal Reserve Bank Stock represents an equity interest in a FHLB of FRB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).
+ References
No definition available.
+ Details**Name:**fnlc_RestrictedEquitySecuritiesAtCost**Namespace Prefix:**fnlc_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Fair value portion of accrued expenses.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.20) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682
+ Details**Name:**us-gaap_AccruedLiabilitiesFairValueDisclosure**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount to be repaid to the counterparty to the repurchase agreement when the carrying amount (or market value, if higher than the carrying amount) of securities or other assets sold under the repurchase agreement exceeds 10 percent of total assets.
+ 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.(m)(1)(i)(A)(ii)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690
+ Details**Name:**us-gaap_AssetsSoldUnderAgreementsToRepurchaseRepurchaseLiability**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.
+ References
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.
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| - Definition
Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.
+ References
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.
+ References
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of money in accounts that may bear interest and that the depositor is entitled to withdraw at any time without prior notice.
+ References
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.
+ References
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of deposits in accounts that offer many of the same services as checking accounts although transactions may be somewhat more limited, share some of the characteristics of a money market fund and are insured by the Federal government, also known as money market accounts.
+ References
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of deposits in interest-bearing transaction accounts at banks or savings and loans, that are restricted in regard to ownership and can usually only be held by individuals, nonprofit entities and governments. Negotiable order of withdrawal accounts differ from money market demand accounts as they typically have higher reserve requirements and no limit on the number of checks that can be written.
+ References
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| - Definition
Amount of interest bearing deposits with no stated maturity, which may include passbook and statement savings accounts and money-market deposit accounts (MMDAs).
+ References
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.
+ References
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| - 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.
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| - Definition
Including both current and noncurrent portions, Federal Home Loan Bank borrowings initially due beyond one year or beyond the normal operating cycle if longer.
+ References
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|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.
+ References
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Fair value of investments in debt securities classified as held-to-maturity.
+ References
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| - Definition
For banks and other depository institutions (including Federal Reserve Banks, if applicable): Interest-bearing deposits in other financial institutions for relatively short periods of time including, for example, certificates of deposits, which are presented separately from cash on the balance sheet.
+ References
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| - Definition
Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.
+ References
No definition available.
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| - Definition
Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.
+ References
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| - Definition
Amount, after allowance for bad debt, of loan receivables held-for-sale that are not part of a disposal group. Excludes loans and leases covered under loss sharing agreements and loans classified as debt securities.
+ References
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amortized amount of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.
+ References
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| - Definition
Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.
+ References
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