Basis of Presentation	3 Months Ended
Basis of Presentation	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The First Bancorp, Inc. ("the Company") is a financial holding company that owns all of the common stock of First National Bank ("the Bank"). The accompanying unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of Management, all adjustments (consisting of normally recurring accruals) considered necessary for a fair presentation have been included. All significant intercompany transactions and balances are eliminated in consolidation. The income reported for the 2020 period is not necessarily indicative of the results that may be expected for the year ending December 31, 2020. For further information, refer to the consolidated financial statements and notes included in the Company's annual report on Form 10-K for the year ended December 31, 2019. Risks and Uncertainties Local, U.S., and world governments have encouraged self–isolation to curtail the spread of the global pandemic, coronavirus disease (COVID–19) by mandating the temporary shut–down of business in many sectors and imposing limitations on travel and size and duration of group meetings. Most industries are experiencing disruption to business operations and the impact of reduced consumer spending. There is unprecedented uncertainty surrounding the duration of the pandemic, its potential economic ramifications, and any government actions to mitigate them. The Company’s business, financial condition and results of operations generally rely upon the ability of the Bank’s borrowers to repay their loans, the value of collateral underlying the Bank’s secured loans, and demand for loans and other products and services the Bank offers, which are highly dependent on the business environment in the Bank’s primary markets where it operates and in the United States as a whole. The Bank's primary market is the State of Maine, which relies upon tourism for a significant percentage of its economic activity. COVID-19 is expected to adversely impact the tourism industry to a greater degree than other industries, however, an overall impact of COVID-19 on the Maine economy cannot be assessed with any degree of certainty at this time. In addition to loans, demand for other products and services could be impacted by COVID-19. Depositors and other funding sources may be unwilling to renew certificates of deposit or other types of funding, or may only be willing to do so on terms, including higher interest rates, that are materially less favorable than the Bank has experienced in the recent past. Certain fee based activities such as debit card interchange and wealth management activity, could be impacted due to lower activity or market declines. Accordingly, while management expects this matter is likely to have a negative financial impact on the Company's financial position and results of future operations, such potential impact cannot be reasonably estimated as of the date of this report, May 8, 2020. Subsequent Events Events occurring subsequent to March 31, 2020, have been evaluated as to their potential impact to the financial statements.