| **Other Real Estate Owned (Tables)**                        | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
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| **Other Real Estate Owned [Abstract]**                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| Other Real Estate Owned                                     | The following summarizes other real estate owned:As of  December 31, 2012  2011 Real estate acquired in settlement of loans $7,593,000  $4,094,000                                                                                                                                                                                                                                                                                                                                                           |
| Change in Allowance for Losses from Other Real Estate Owned | Changes in the allowance for losses from other real estate owned were as follows:For the years ended December 31, 2012  2011  2010 Balance at beginning of year $436,000  $132,000  $583,000 Losses charged to allowance  (460,000)  (980,000)  (803,000)Provision charged to operating expenses  397,000   1,284,000   352,000 Balance at end of year $373,000  $436,000  $132,000  |

| X                                                                                                                                                                                                                                                                                                                                                                                                                              |
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| - Definition
Tabular disclosure of the change in the allowance for real estate owned and acquired in settlement of troubled loans through surrender or foreclosure during the period.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                              |
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| - Definition
Tabular disclosure of real estate owned and acquired in settlement of troubled loans through surrender or foreclosure.
+ References
No definition available.
+ Details**Name:**fnlc_OtherRealEstateOwnedTableTextBlock**Namespace Prefix:**fnlc_**Data Type:**nonnum:textBlockItemType**Balance Type:**na**Period Type:**duration |
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