Summary of Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2012
Summary of Significant Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation. The accompanying Consolidated Financial Statements include the accounts of the Company, the Bank (a wholly-owned bank subsidiary), and Acadia Trust, N.A. (a wholly-owned non-bank subsidiary). All intercompany accounts and transactions have been eliminated in consolidation. Assets held by the non-bank subsidiary in a fiduciary capacity are not assets of the Company and, therefore, are not included in the Consolidated Statements of Condition. The Company also owns 100% of the common stock of Camden Capital Trust A and Union Bankshares Capital Trust I. These entities are unconsolidated subsidiaries of the Company.
Reclassification and presentation	Reclassifications. Certain reclassifications have been made to prior year amounts to conform to the current year presentation.
Use of Estimates in the Preparation of Financial Statements	Use of Estimates in the Preparation of Financial Statements. The preparation of the financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could vary from these estimates. Several estimates are particularly critical and are susceptible to significant near-term change, including the allowance for loan losses ("ALL"), other real estate owned ("OREO"), postretirement benefits and asset impairment judgments including other-than-temporary declines in the value of securities and the recoverability of goodwill, other intangible assets and deferred tax assets.
Subsequent Events	Subsequent Events. The Company has evaluated events and transactions subsequent to December 31, 2012 for potential recognition or disclosure as required by GAAP.
Cash and Cash Equivalents	Cash and Cash Equivalents. For the purposes of reporting cash flows, cash and cash equivalents consist of cash on hand and amounts due from banks. The Bank is required by the Federal Reserve System to maintain non-interest bearing cash reserves equal to a percentage of deposits. The Company maintains the reserve balances in cash on hand or at the Federal Reserve Bank ("FRB").
Securities	Securities. Marketable equity and debt securities are classified as either available for sale securities or held to maturity securities. Management determines the classification of a security at the time of its purchase. Securities which the Company has the positive intent and ability to hold to maturity are classified as held to maturity and reported at amortized cost. All other securities are classified as available for sale and reported at fair value. Unrealized gains and temporary unrealized losses on securities classified as available for sale are reported on an after-tax basis in shareholders' equity as accumulated other comprehensive income or loss. Federal Home Loan Bank ("FHLB") and FRB stocks are non-marketable equity securities reported at cost and evaluated for impairment. Premiums and discounts are recognized in interest income using the interest method over the period to maturity. Security transactions are recorded on the trade date. Realized gains and losses are determined using the specific identification method and reported in non-interest income. Management conducts a periodic review and evaluation of the securities portfolio to determine if the decline in fair value of any security appears to be other-than-temporary. The factors considered by management in its periodic review include, but are not limited to: the length of time and the extent to which the fair value has been less than cost, the financial condition and near-term prospects of the issuer, the ratings of the security, whether the decline in fair value appears to be issuer specific or, alternatively, a reflection of general market or industry conditions, and the Company's intent and ability to hold the security for a period of time sufficient to allow for a recovery in fair value. Declines in the fair value of individual equity securities that are deemed to be other-than-temporary are reflected in non-interest income when identified. For individual debt securities where the Company does not intend to sell the security and it is not more likely than not that the Company will be required to sell the security before recovery of its amortized cost basis, the other-than-temporary decline in the fair value of the debt security related to (i) credit loss is recognized in non-interest income and (ii) other factors is recognized in other comprehensive income or loss. Credit loss is deemed to exist if the present value of expected future cash flows using the interest rate at acquisition is less than the amortized cost basis of the debt security. For individual debt securities where the Company intends to sell the security or more likely than not will be required to sell the security before recovery of its amortized cost, the other-than-temporary impairment is recognized in earnings equal to the entire difference between the security's cost basis and its fair value at the date of the consolidated statement of condition. The Company is a member of the FHLB of Boston ("FHLBB"). As a requirement of membership, the Company must own a minimum amount of FHLB stock based on the level of its FHLB advances. No market exists for shares of the FHLB and therefore they are carried at par value. FHLB stock may be redeemed at par value five years following termination of FHLB membership, subject to limitations which may be imposed by the FHLB or its regulator, the Federal Housing Finance Agency, to maintain capital adequacy of the FHLB. While the Company currently has no intentions to terminate its FHLB membership, the ability to redeem its investment in FHLB stock would be subject to the conditions imposed by the FHLB.
Loans and Allowance for Loan Losses	Loans and Allowance for Loan Losses. At March 31, 2012, the Company elected the fair value option for its loans held for sale and as such the fair value for loans held for sale is determined using quoted secondary market prices or executed sales agreements. At December 31, 2011, loans held for sale are reported at the lower of cost or market value in the aggregate, with any adjustment for net unrealized losses reported in non-interest income. All other loans in the aggregate are reported at amortized cost adjusted for any charge-offs, the ALL and any deferred fees or costs. From time to time, management identifies and designates certain residential mortgage loans (either newly originated mortgage loans or held in the loan portfolio) for sale, and, accordingly, these loans are transferred to loans held for sale. The ALL is established through provisions for credit losses charged to income. Losses on loans, including impaired loans, are charged to the ALL when all or a portion of a loan is deemed to be uncollectible. Recoveries of loans previously charged off are credited to the ALL when realized. In determining the appropriate level of ALL, the Company uses a methodology to systematically measure the amount of estimated loan loss exposure inherent in the loan portfolio. The methodology includes four elements: (1) identification of loss allocations for certain specific loans, (2) loss allocation factors for certain loan types based on credit grade and loss experience, (3) general loss allocations for other environmental factors, and (4) the unallocated portion of the allowance. The specific component relates to loans that are classified as doubtful, substandard or special mention. For such loans that are also classified as impaired, an allowance is established when the discounted cash flows (or collateral value or observable market price) of the impaired loan is lower than the carrying value of that loan. The methodology is in accordance with accounting principles generally accepted in the United States of America. The Company uses a risk rating system to determine the credit quality of loans and applies the related loss allocation factors. In assessing the risk rating of a particular loan, the Company considers, among other factors, the obligor's debt capacity, financial condition, the level of the obligor's earnings, the amount and sources of repayment, the performance with respect to loan terms, the adequacy of collateral, the level and nature of contingent liabilities, management strength, and the industry in which the obligor operates. These factors are based on an evaluation of historical information, as well as subjective assessment and interpretation of current conditions. Emphasizing one factor over another, or considering additional factors that may be relevant in determining the risk rating of a particular loan but which are not currently an explicit part of our methodology, could impact the risk rating assigned to that loan. The Company periodically reassesses and revises the loss allocation factors used in the assignment of loss exposure to appropriately reflect the analysis of loss experience. Portfolios of more homogenous populations of loans including home equity and consumer loans are analyzed as groups taking into account delinquency rates and other economic conditions which may affect the ability of borrowers to meet debt service requirements, including interest rates and energy costs. The Company also considers the results of regulatory examinations, historical loss ranges, portfolio composition, and other changes in the portfolio. An additional allocation is determined based on a judgmental process whereby management considers qualitative and quantitative assessments of other environmental factors. An unallocated portion of the total allowance is maintained to allow for shifts in portfolio composition and to account for uncertainty in the economic environment. Since the methodology is based upon historical experience and trends as well as management's judgment, factors may arise that result in different estimations. Significant factors that could give rise to changes in these estimates may include, but are not limited to, changes in economic conditions in the Company's market area, concentration of risk, declines in local property values, and results of regulatory examinations. Loans past due 30 days or more are considered delinquent. In general, consumer loans will be charged off if the loan is delinquent for 90 consecutive days. Commercial and real estate loans may be charged off in part or in full if they appear uncollectible. A loan is considered impaired when, based on current information and events, it is probable that the Company will be unable to collect all principal and interest due according to the contractual terms of the loan. Impairment is measured on a loan by loan basis for commercial, commercial real estate, and construction loans by one of three measures: the present value of expected future cash flows discounted at the loan's effective interest rate; the loan's observable market price; or the fair value of the collateral if the loan is collateral dependent. Large groups of homogeneous loans are collectively evaluated for impairment. As such, the Company does not typically identify individual loans within these groupings as impaired loans for impairment evaluation and disclosure.
Interest and Fees on Loans	Interest and Fees on Loans. Interest on loans is accrued at the contractual rate and credited to income based upon the principal amount outstanding. Loan origination fees received and certain direct loan origination costs are deferred and recognized in interest income as an adjustment of loan yield. A loan is classified as non-accrual generally when it becomes 90 days past due as to interest or principal payments. All previously accrued but unpaid interest on non-accrual loans is reversed from interest income in the current period. Interest payments received on non-accrual loans (including impaired loans) are applied as a reduction of principal. A loan remains on non-accrual status until all principal and interest amounts contractually due are brought current and future payments are reasonably assured.
Goodwill and Core Deposit Intangible	Goodwill and Core Deposit Intangible. Goodwill represents the excess of the cost of an acquisition over the fair value of the net assets acquired. Goodwill is not subject to amortization but rather is evaluated at least annually for impairment. Any impairment write-down would be charged to non-interest expense. Goodwill is evaluated at least annually for impairment utilizing several standard valuation techniques, including discounted cash flow analyses, bank merger multiples, and an estimation of the impact of business conditions and investor activities on the long-term value of the goodwill. Core deposit intangible represents the estimated value of acquired customer relationships and is amortized on a straight-line basis over the estimated life of those relationships (5 to10 years from the acquisition dates). On an ongoing basis, management reviews the valuation and amortization of intangible assets to determine possible impairment.
Bank-Owned Life Insurance	Bank-Owned Life Insurance. Bank-owned life insurance represents the cash surrender value ("CSV") of life insurance policies on the lives of certain active and retired employees where the Company is the beneficiary. The CSV of the policies is recorded as an asset. Increases in the CSV of the policies, as well as death benefits received, net of any CSV, are recorded in non-interest income, and are not subject to income taxes.
Premises and Equipment	Premises and Equipment. Premises and equipment are stated at cost, less accumulated depreciation and amortization, and fair value adjustments. Depreciation and amortization are computed on the straight-line method over the estimated useful lives of the related assets. Leasehold improvements are amortized over the term of the respective lease or the estimated life of the improvement, whichever is shorter.
OREO	OREO. OREO properties acquired through foreclosure or deed-in-lieu of foreclosure are recorded initially at estimated fair value less costs to sell. Any write-down of the recorded investment in the related loan is charged to the ALL upon transfer to OREO. Thereafter, any further declines in the property's values are recorded against current earnings. Upon acquisition of a property, a current appraisal or a broker's opinion is used to substantiate fair value for the property.
Mortgage Servicing	Mortgage Servicing. Servicing assets are recognized as separate assets when servicing rights are acquired through the sale of residential mortgage loans with servicing retained. Capitalized servicing rights, which are reported in other assets, are initially recorded at fair value and are amortized in proportion to, and over the period of, the estimated future servicing of the underlying mortgages. Servicing assets are evaluated for impairment based upon the fair value of the rights as compared to amortized cost. Impairment is determined by stratifying rights by predominant characteristics, such as interest rates and terms. Fair value is determined using prices for similar assets with similar characteristics, when available, or based upon discounted cash flows using market-based assumptions. Impairment for an individual stratum is recognized through earnings to the extent that fair value is less than the capitalized amount for the stratum.
Other Borrowed Funds	Other Borrowed Funds. Other borrowed funds consist of commercial and retail repurchase agreements, FHLB overnight borrowings, federal funds purchased, line of credit advances, notes payable, and treasury, tax and loan deposits. Retail repurchase agreements generally mature within 30 days and are reflected at the amount of cash received in connection with the transaction. Commercial repurchase agreements are callable quarterly, generally 6 to 24 months after issuance, and mature within five years. The Company may be required to provide additional collateral based on the fair value of the underlying securities. Treasury, tax and loan deposits generally do not have fixed maturity dates.
Income Taxes	Income Taxes. Income taxes are accounted for using the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the future tax implications attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. If current available information raises doubt as to the realization of the deferred tax assets, a valuation allowance is established. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date.
Earnings per Share	Earnings per Share. Basic earnings per common share ("EPS") excludes dilution and is computed by dividing net income applicable to common stock by the weighted average number of common shares outstanding for the year. Diluted EPS reflects the potential dilution that could occur if certain securities or other contracts to issue common stock (such as stock options) were exercised or converted into additional common shares that would then share in the earnings of the Company. Diluted EPS is computed by dividing net income applicable to common stock by the weighted average number of common shares outstanding for the year, plus an incremental number of common-equivalent shares computed using the treasury stock method. Unvested share-based payment awards which include the right to receive non-forfeitable dividends are considered to participate with common stock in undistributed earnings for purposes of computing EPS. Restricted share grants and management stock purchase grants are considered participating securities for this purpose. Accordingly, the Company is required to calculate basic and diluted EPS amounts under the two-class method. Calculations of EPS under the two-class method (i) exclude any dividends paid or owed on participating securities and any undistributed earnings considered to be attributable to participating securities from the numerator and (ii) exclude the dilutive impact of the participating securities from the denominator.
Postretirement and Supplemental Retirement Plans	Postretirement and Supplemental Retirement Plans. The Company sponsors a postretirement health care plan and life insurance to certain eligible retired employees. The cost of providing postretirement benefits is accrued during the active service period of the employee. A supplemental retirement plan is also maintained for certain officers of the Company. The supplemental retirement plan is accrued on a current basis and recognizes costs over the estimated employee service period.
Stock-Based Compensation	Stock-Based Compensation. The fair value of restricted stock and stock options is determined on the date of grant and amortized to compensation expense, with a corresponding increase in common stock, over the longer of the service period or performance period, but in no event beyond an employee's retirement date. For performance-based restricted stock, the Company estimates the degree to which performance conditions will be met to determine the number of shares that will vest and the related compensation expense. Compensation expense is adjusted in the period such estimates change. Non-forfeitable dividends, if any, paid on shares of restricted stock are recorded to retained earnings for shares that are expected to vest and to compensation expense for shares that are not expected to vest.
Off-Balance Sheet Credit Related Financial Instruments	Off-Balance Sheet Credit Related Financial Instruments. In the ordinary course of business, the Company enters into commitments to extend credit, including commercial letters of credit and standby letters of credit. Such financial instruments are recorded as loans when they are funded.
Derivative Financial Instruments Designated as Hedges	Derivative Financial Instruments Designated as Hedges. The Company recognizes all derivatives in the Consolidated Statements of Condition at fair value. On the date the Company enters into the derivative contract, the Company designates the derivative as a hedge of either a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability ("cash flow hedge"), a hedge of the fair value of a recognized asset or liability or of an unrecognized firm commitment ("fair value hedge"), or a held for trading instrument ("trading instrument"). The Company formally documents relationships between hedging instruments and hedged items, as well as its risk management objectives and strategy for undertaking various hedge transactions. The Company also assesses, both at the hedge's inception and on an ongoing basis, whether the derivatives that are used in hedging transactions are effective in offsetting changes in cash flows or fair values of hedged items. Changes in fair value of a derivative that is effective and that qualifies as a cash flow hedge are recorded in other comprehensive income or loss and are reclassified into earnings when the forecasted transaction or related cash flows affect earnings. Changes in fair value of a derivative that qualifies as a fair value hedge and the change in fair value of the hedged item are both recorded in earnings and offset each other when the transaction is effective. Those derivatives that are classified as trading instruments are recorded at fair value with changes in fair value recorded in earnings. The Company discontinues hedge accounting when it determines that the derivative is no longer effective in offsetting changes in the cash flows of the hedged item, that it is unlikely that the forecasted transaction will occur, or that the designation of the derivative as a hedging instrument is no longer appropriate.
Segment Reporting	Segment Reporting. The Company, through its bank and non-bank subsidiaries, provides a broad range of financial services to individuals and companies in the State of Maine. These services include lending, checking, savings and time deposits, cash management, brokerage and trust services. While the Company's management monitors operations of each subsidiary, substantially all revenues and profits are derived by the Bank from banking products and services. Revenues and profits derived, and assets owned by Acadia Trust, N.A. are less than 10% of the consolidated Company totals and, accordingly, the Company and its subsidiaries are considered by management to be aggregated in one reportable operating segment.
Recent Accounting Pronouncements	Recent Accounting Pronouncements. In May 2011, the FASB issued Accounting Standards Update ("ASU") No. 2011-04, Fair Value Measurement (Topic 820): Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRs. This ASU clarifies how to measure fair value, but does not require additional fair value measurement and is not intended to affect current valuation practices outside of financial reporting. However, additional information and disclosure are required for transfers between Level 1 and Level 2, the sensitivity of a fair value measurement categorized as Level 3, and the categorization of items that are not measured at fair value by level of the fair value hierarchy. The guidance is effective during interim and annual reporting periods beginning after December 15, 2011. Other than expanded disclosures, the implementation of ASU No. 2011-04 did not have a material effect on the Company's consolidated financial statements. In June 2011, the FASB issued ASU No. 2011-05, Comprehensive Income (Topic 220): Presentation of Comprehensive Income. This ASU requires that all non-owner changes in shareholders' equity be presented either in a single continuous statement of comprehensive income or in two separate but consecutive statements. In the two-statement approach, the first statement should present total net income and its components followed consecutively by a second statement that should present total other comprehensive income, the components of other comprehensive income, and the total of comprehensive income. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2011. Other than matters of presentation, the adoption of this new guidance did not have a material effect on the Company's consolidated financial statements. In August 2011, the FASB issued ASU No. 2011-08, Intangibles - Goodwill and Other (Topic 350): Testing Goodwill for Impairment. This ASU permits an entity to first assess qualitative factors in determining whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount as a basis for identifying whether it is necessary to perform the two-step goodwill impairment test described in Topic 350. Previous guidance under Topic 350 required an entity to test goodwill for impairment, on at least an annual basis, by comparing the fair value of a reporting unit with its carrying amount, including goodwill (step one). If the fair value of a reporting unit is less than its carrying amount, then the second step of the test must be performed to measure the amount of the impairment loss, if any. Under the amendments in this ASU, an entity is not required to calculate the fair value of a reporting unit unless the entity determines that it is more likely than not that its fair value is less than its carrying amount. This guidance is effective for annual periods for fiscal years ending after December 15, 2011, with early adoption permitted. The adoption of this new guidance did not have a material effect on the Company's consolidated financial statements. In July 2012, the FASB issued ASU No. 2012-02, Intangibles-Goodwill and Other (Topic 350): Testing Indefinite-Lived Assets for Impairment. This ASU reduces the cost and complexity of performing an impairment test for indefinite-lived intangible assets by simplifying how an entity tests those assets for impairment and to improve consistency in impairment testing guidance among long-lived asset categories. The amendments permit an entity first to assess qualitative factors to determine whether it is more likely than not that an indefinite-lived intangible asset is impaired as a basis for determining whether it is necessary to perform the quantitative impairment test in accordance with Subtopic 350-30, Intangibles - Goodwill and Other - General Intangibles Other than Goodwill. The more-likely-than-not threshold is defined as having a likelihood of more than 50 percent. This guidance is effective for annual and interim impairment tests performed for fiscal years beginning after September 15, 2012. Early adoption is permitted, including for annual and interim impairment tests performed as of a date before July 27, 2012, if a public entity's financial statements for the most recent annual or interim period have not yet been issued or, for nonpublic entities, have not yet been made available for issuance. The adoption of this new guidance did not have a material effect on the Company's consolidated financial statements. In January 2013, the FASB issued ASU No. 2013-01, Balance Sheet (Topic 210): Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities. This ASU clarifies that the scope of Update 2011-11 applies to derivatives accounted for in accordance with Topic 815, Derivatives and Hedging, including bifurcated embedded derivatives, repurchase agreements and reverse repurchase agreements, and securities borrowing and securities lending transactions that are either offset in accordance with Section 210-20-45 or Section 815-10-45 or subject to an enforceable master netting arrangement or similar agreement. This guidance is effective for fiscal years beginning on or after January 1, 2013, and interim periods within those annual periods. The Company believes the clarifications provided in ASU No. 2013-01 will not have a material effect on the Company's consolidated financial statements. In February 2013, the FASB issued ASU No. 2013-02, Comprehensive Income (Topic 220): Reporting of Amounts Reclassified out of Accumulated Other Comprehensive Income. This ASU improves the reporting of reclassifications out of accumulated other comprehensive income. The amendments in the ASU seek to attain that objective by requiring an entity to report the effect of significant reclassifications out of accumulated other comprehensive income on the respective line items in net income if the amount being reclassified is required under U.S. generally accepted accounting principles ("GAAP") to be reclassified in its entirety to net income. For other amounts that are not required under GAAP to be reclassified in their entirety to net income in the same reporting period, an entity is required to cross-reference other disclosures required under GAAP that provide additional detail about those amounts. This guidance is effective for reporting periods beginning after December 15, 2012, with early adoption permitted. Other than matters of presentation, the Company believes the adoption of this new guidance will not have a material effect on the Company's consolidated financial statements.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2012

Summary of Significant Accounting Policies [Abstract]

Principles of Consolidation. The accompanying Consolidated Financial Statements include the accounts of the Company, the Bank (a wholly-owned bank subsidiary), and Acadia Trust, N.A. (a wholly-owned non-bank subsidiary). All intercompany accounts and transactions have been eliminated in consolidation. Assets held by the non-bank subsidiary in a fiduciary capacity are not assets of the Company and, therefore, are not included in the Consolidated Statements of Condition. The Company also owns 100% of the common stock of Camden Capital Trust A and Union Bankshares Capital Trust I. These entities are unconsolidated subsidiaries of the Company.

Reclassification and presentation

Reclassifications. Certain reclassifications have been made to prior year amounts to conform to the current year presentation.

Use of Estimates in the Preparation of Financial Statements

Use of Estimates in the Preparation of Financial Statements. The preparation of the financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Actual results could vary from these estimates. Several estimates are particularly critical and are susceptible to significant near-term change, including the allowance for loan losses ("ALL"), other real estate owned ("OREO"), postretirement benefits and asset impairment judgments including other-than-temporary declines in the value of securities and the recoverability of goodwill, other intangible assets and deferred tax assets.

Subsequent Events

Subsequent Events. The Company has evaluated events and transactions subsequent to December 31, 2012 for potential recognition or disclosure as required by GAAP.

Cash and Cash Equivalents

Cash and Cash Equivalents. For the purposes of reporting cash flows, cash and cash equivalents consist of cash on hand and amounts due from banks. The Bank is required by the Federal Reserve System to maintain non-interest bearing cash reserves equal to a percentage of deposits. The Company maintains the reserve balances in cash on hand or at the Federal Reserve Bank ("FRB").

Securities

Securities. Marketable equity and debt securities are classified as either available for sale securities or held to maturity securities. Management determines the classification of a security at the time of its purchase.

Securities which the Company has the positive intent and ability to hold to maturity are classified as held to maturity and reported at amortized cost. All other securities are classified as available for sale and reported at fair value. Unrealized gains and temporary unrealized losses on securities classified as available for sale are reported on an after-tax basis in shareholders' equity as accumulated other comprehensive income or loss. Federal Home Loan Bank ("FHLB") and FRB stocks are non-marketable equity securities reported at cost and evaluated for impairment.

Premiums and discounts are recognized in interest income using the interest method over the period to maturity. Security transactions are recorded on the trade date. Realized gains and losses are determined using the specific identification method and reported in non-interest income.

Management conducts a periodic review and evaluation of the securities portfolio to determine if the decline in fair value of any security appears to be other-than-temporary. The factors considered by management in its periodic review include, but are not limited to: the length of time and the extent to which the fair value has been less than cost, the financial condition and near-term prospects of the issuer, the ratings of the security, whether the decline in fair value appears to be issuer specific or, alternatively, a reflection of general market or industry conditions, and the Company's intent and ability to hold the security for a period of time sufficient to allow for a recovery in fair value.

Declines in the fair value of individual equity securities that are deemed to be other-than-temporary are reflected in non-interest income when identified. For individual debt securities where the Company does not intend to sell the security and it is not more likely than not that the Company will be required to sell the security before recovery of its amortized cost basis, the other-than-temporary decline in the fair value of the debt security related to (i) credit loss is recognized in non-interest income and (ii) other factors is recognized in other comprehensive income or loss. Credit loss is deemed to exist if the present value of expected future cash flows using the interest rate at acquisition is less than the amortized cost basis of the debt security. For individual debt securities where the Company intends to sell the security or more likely than not will be required to sell the security before recovery of its amortized cost, the other-than-temporary impairment is recognized in earnings equal to the entire difference between the security's cost basis and its fair value at the date of the consolidated statement of condition.

The Company is a member of the FHLB of Boston ("FHLBB"). As a requirement of membership, the Company must own a minimum amount of FHLB stock based on the level of its FHLB advances. No market exists for shares of the FHLB and therefore they are carried at par value. FHLB stock may be redeemed at par value five years following termination of FHLB membership, subject to limitations which may be imposed by the FHLB or its regulator, the Federal Housing Finance Agency, to maintain capital adequacy of the FHLB. While the Company currently has no intentions to terminate its FHLB membership, the ability to redeem its investment in FHLB stock would be subject to the conditions imposed by the FHLB.

Loans and Allowance for Loan Losses

Loans and Allowance for Loan Losses. At March 31, 2012, the Company elected the fair value option for its loans held for sale and as such the fair value for loans held for sale is determined using quoted secondary market prices or executed sales agreements. At December 31, 2011, loans held for sale are reported at the lower of cost or market value in the aggregate, with any adjustment for net unrealized losses reported in non-interest income. All other loans in the aggregate are reported at amortized cost adjusted for any charge-offs, the ALL and any deferred fees or costs. From time to time, management identifies and designates certain residential mortgage loans (either newly originated mortgage loans or held in the loan portfolio) for sale, and, accordingly, these loans are transferred to loans held for sale.

The ALL is established through provisions for credit losses charged to income. Losses on loans, including impaired loans, are charged to the ALL when all or a portion of a loan is deemed to be uncollectible. Recoveries of loans previously charged off are credited to the ALL when realized.

In determining the appropriate level of ALL, the Company uses a methodology to systematically measure the amount of estimated loan loss exposure inherent in the loan portfolio. The methodology includes four elements: (1) identification of loss allocations for certain specific loans, (2) loss allocation factors for certain loan types based on credit grade and loss experience, (3) general loss allocations for other environmental factors, and (4) the unallocated portion of the allowance. The specific component relates to loans that are classified as doubtful, substandard or special mention. For such loans that are also classified as impaired, an allowance is established when the discounted cash flows (or collateral value or observable market price) of the impaired loan is lower than the carrying value of that loan. The methodology is in accordance with accounting principles generally accepted in the United States of America.

The Company uses a risk rating system to determine the credit quality of loans and applies the related loss allocation factors. In assessing the risk rating of a particular loan, the Company considers, among other factors, the obligor's debt capacity, financial condition, the level of the obligor's earnings, the amount and sources of repayment, the performance with respect to loan terms, the adequacy of collateral, the level and nature of contingent liabilities, management strength, and the industry in which the obligor operates. These factors are based on an evaluation of historical information, as well as subjective assessment and interpretation of current conditions. Emphasizing one factor over another, or considering additional factors that may be relevant in determining the risk rating of a particular loan but which are not currently an explicit part of our methodology, could impact the risk rating assigned to that loan. The Company periodically reassesses and revises the loss allocation factors used in the assignment of loss exposure to appropriately reflect the analysis of loss experience. Portfolios of more homogenous populations of loans including home equity and consumer loans are analyzed as groups taking into account delinquency rates and other economic conditions which may affect the ability of borrowers to meet debt service requirements, including interest rates and energy costs. The Company also considers the results of regulatory examinations, historical loss ranges, portfolio composition, and other changes in the portfolio. An additional allocation is determined based on a judgmental process whereby management considers qualitative and quantitative assessments of other environmental factors. An unallocated portion of the total allowance is maintained to allow for shifts in portfolio composition and to account for uncertainty in the economic environment.

Since the methodology is based upon historical experience and trends as well as management's judgment, factors may arise that result in different estimations. Significant factors that could give rise to changes in these estimates may include, but are not limited to, changes in economic conditions in the Company's market area, concentration of risk, declines in local property values, and results of regulatory examinations.

Loans past due 30 days or more are considered delinquent. In general, consumer loans will be charged off if the loan is delinquent for 90 consecutive days. Commercial and real estate loans may be charged off in part or in full if they appear uncollectible.

A loan is considered impaired when, based on current information and events, it is probable that the Company will be unable to collect all principal and interest due according to the contractual terms of the loan. Impairment is measured on a loan by loan basis for commercial, commercial real estate, and construction loans by one of three measures: the present value of expected future cash flows discounted at the loan's effective interest rate; the loan's observable market price; or the fair value of the collateral if the loan is collateral dependent. Large groups of homogeneous loans are collectively evaluated for impairment. As such, the Company does not typically identify individual loans within these groupings as impaired loans for impairment evaluation and disclosure.

Interest and Fees on Loans

Interest and Fees on Loans. Interest on loans is accrued at the contractual rate and credited to income based upon the principal amount outstanding. Loan origination fees received and certain direct loan origination costs are deferred and recognized in interest income as an adjustment of loan yield. A loan is classified as non-accrual generally when it becomes 90 days past due as to interest or principal payments. All previously accrued but unpaid interest on non-accrual loans is reversed from interest income in the current period. Interest payments received on non-accrual loans (including impaired loans) are applied as a reduction of principal. A loan remains on non-accrual status until all principal and interest amounts contractually due are brought current and future payments are reasonably assured.

Goodwill and Core Deposit Intangible

Goodwill and Core Deposit Intangible. Goodwill represents the excess of the cost of an acquisition over the fair value of the net assets acquired. Goodwill is not subject to amortization but rather is evaluated at least annually for impairment. Any impairment write-down would be charged to non-interest expense. Goodwill is evaluated at least annually for impairment utilizing several standard valuation techniques, including discounted cash flow analyses, bank merger multiples, and an estimation of the impact of business conditions and investor activities on the long-term value of the goodwill.

Core deposit intangible represents the estimated value of acquired customer relationships and is amortized on a straight-line basis over the estimated life of those relationships (5 to10 years from the acquisition dates). On an ongoing basis, management reviews the valuation and amortization of intangible assets to determine possible impairment.

Bank-Owned Life Insurance

Bank-Owned Life Insurance. Bank-owned life insurance represents the cash surrender value ("CSV") of life insurance policies on the lives of certain active and retired employees where the Company is the beneficiary. The CSV of the policies is recorded as an asset. Increases in the CSV of the policies, as well as death benefits received, net of any CSV, are recorded in non-interest income, and are not subject to income taxes.

Premises and Equipment

Premises and Equipment. Premises and equipment are stated at cost, less accumulated depreciation and amortization, and fair value adjustments. Depreciation and amortization are computed on the straight-line method over the estimated useful lives of the related assets. Leasehold improvements are amortized over the term of the respective lease or the estimated life of the improvement, whichever is shorter.

OREO

OREO. OREO properties acquired through foreclosure or deed-in-lieu of foreclosure are recorded initially at estimated fair value less costs to sell. Any write-down of the recorded investment in the related loan is charged to the ALL upon transfer to OREO. Thereafter, any further declines in the property's values are recorded against current earnings. Upon acquisition of a property, a current appraisal or a broker's opinion is used to substantiate fair value for the property.

Mortgage Servicing

Mortgage Servicing. Servicing assets are recognized as separate assets when servicing rights are acquired through the sale of residential mortgage loans with servicing retained. Capitalized servicing rights, which are reported in other assets, are initially recorded at fair value and are amortized in proportion to, and over the period of, the estimated future servicing of the underlying mortgages. Servicing assets are evaluated for impairment based upon the fair value of the rights as compared to amortized cost. Impairment is determined by stratifying rights by predominant characteristics, such as interest rates and terms. Fair value is determined using prices for similar assets with similar characteristics, when available, or based upon discounted cash flows using market-based assumptions. Impairment for an individual stratum is recognized through earnings to the extent that fair value is less than the capitalized amount for the stratum.

Other Borrowed Funds

Other Borrowed Funds. Other borrowed funds consist of commercial and retail repurchase agreements, FHLB overnight borrowings, federal funds purchased, line of credit advances, notes payable, and treasury, tax and loan deposits. Retail repurchase agreements generally mature within 30 days and are reflected at the amount of cash received in connection with the transaction. Commercial repurchase agreements are callable quarterly, generally 6 to 24 months after issuance, and mature within five years. The Company may be required to provide additional collateral based on the fair value of the underlying securities. Treasury, tax and loan deposits generally do not have fixed maturity dates.

Income Taxes

Income Taxes. Income taxes are accounted for using the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the future tax implications attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. If current available information raises doubt as to the realization of the deferred tax assets, a valuation allowance is established. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date.

Earnings per Share

Earnings per Share. Basic earnings per common share ("EPS") excludes dilution and is computed by dividing net income applicable to common stock by the weighted average number of common shares outstanding for the year. Diluted EPS reflects the potential dilution that could occur if certain securities or other contracts to issue common stock (such as stock options) were exercised or converted into additional common shares that would then share in the earnings of the Company. Diluted EPS is computed by dividing net income applicable to common stock by the weighted average number of common shares outstanding for the year, plus an incremental number of common-equivalent shares computed using the treasury stock method.

Unvested share-based payment awards which include the right to receive non-forfeitable dividends are considered to participate with common stock in undistributed earnings for purposes of computing EPS. Restricted share grants and management stock purchase grants are considered participating securities for this purpose. Accordingly, the Company is required to calculate basic and diluted EPS amounts under the two-class method. Calculations of EPS under the two-class method (i) exclude any dividends paid or owed on participating securities and any undistributed earnings considered to be attributable to participating securities from the numerator and (ii) exclude the dilutive impact of the participating securities from the denominator.

Postretirement and Supplemental Retirement Plans

Postretirement and Supplemental Retirement Plans. The Company sponsors a postretirement health care plan and life insurance to certain eligible retired employees. The cost of providing postretirement benefits is accrued during the active service period of the employee. A supplemental retirement plan is also maintained for certain officers of the Company. The supplemental retirement plan is accrued on a current basis and recognizes costs over the estimated employee service period.

Stock-Based Compensation

Stock-Based Compensation. The fair value of restricted stock and stock options is determined on the date of grant and amortized to compensation expense, with a corresponding increase in common stock, over the longer of the service period or performance period, but in no event beyond an employee's retirement date. For performance-based restricted stock, the Company estimates the degree to which performance conditions will be met to determine the number of shares that will vest and the related compensation expense. Compensation expense is adjusted in the period such estimates change. Non-forfeitable dividends, if any, paid on shares of restricted stock are recorded to retained earnings for shares that are expected to vest and to compensation expense for shares that are not expected to vest.

Off-Balance Sheet Credit Related Financial Instruments

Off-Balance Sheet Credit Related Financial Instruments. In the ordinary course of business, the Company enters into commitments to extend credit, including commercial letters of credit and standby letters of credit. Such financial instruments are recorded as loans when they are funded.

Derivative Financial Instruments Designated as Hedges

Derivative Financial Instruments Designated as Hedges. The Company recognizes all derivatives in the Consolidated Statements of Condition at fair value. On the date the Company enters into the derivative contract, the Company designates the derivative as a hedge of either a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability ("cash flow hedge"), a hedge of the fair value of a recognized asset or liability or of an unrecognized firm commitment ("fair value hedge"), or a held for trading instrument ("trading instrument"). The Company formally documents relationships between hedging instruments and hedged items, as well as its risk management objectives and strategy for undertaking various hedge transactions. The Company also assesses, both at the hedge's inception and on an ongoing basis, whether the derivatives that are used in hedging transactions are effective in offsetting changes in cash flows or fair values of hedged items. Changes in fair value of a derivative that is effective and that qualifies as a cash flow hedge are recorded in other comprehensive income or loss and are reclassified into earnings when the forecasted transaction or related cash flows affect earnings. Changes in fair value of a derivative that qualifies as a fair value hedge and the change in fair value of the hedged item are both recorded in earnings and offset each other when the transaction is effective. Those derivatives that are classified as trading instruments are recorded at fair value with changes in fair value recorded in earnings. The Company discontinues hedge accounting when it determines that the derivative is no longer effective in offsetting changes in the cash flows of the hedged item, that it is unlikely that the forecasted transaction will occur, or that the designation of the derivative as a hedging instrument is no longer appropriate.

Segment Reporting

Segment Reporting. The Company, through its bank and non-bank subsidiaries, provides a broad range of financial services to individuals and companies in the State of Maine. These services include lending, checking, savings and time deposits, cash management, brokerage and trust services. While the Company's management monitors operations of each subsidiary, substantially all revenues and profits are derived by the Bank from banking products and services. Revenues and profits derived, and assets owned by Acadia Trust, N.A. are less than 10% of the consolidated Company totals and, accordingly, the Company and its subsidiaries are considered by management to be aggregated in one reportable operating segment.

Recent Accounting Pronouncements

Recent Accounting Pronouncements. In May 2011, the FASB issued Accounting Standards Update ("ASU") No. 2011-04, Fair Value Measurement (Topic 820): Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRs. This ASU clarifies how to measure fair value, but does not require additional fair value measurement and is not intended to affect current valuation practices outside of financial reporting. However, additional information and disclosure are required for transfers between Level 1 and Level 2, the sensitivity of a fair value measurement categorized as Level 3, and the categorization of items that are not measured at fair value by level of the fair value hierarchy. The guidance is effective during interim and annual reporting periods beginning after December 15, 2011. Other than expanded disclosures, the implementation of ASU No. 2011-04 did not have a material effect on the Company's consolidated financial statements.

In June 2011, the FASB issued ASU No. 2011-05, Comprehensive Income (Topic 220): Presentation of Comprehensive Income. This ASU requires that all non-owner changes in shareholders' equity be presented either in a single continuous statement of comprehensive income or in two separate but consecutive statements. In the two-statement approach, the first statement should present total net income and its components followed consecutively by a second statement that should present total other comprehensive income, the components of other comprehensive income, and the total of comprehensive income. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2011. Other than matters of presentation, the adoption of this new guidance did not have a material effect on the Company's consolidated financial statements.

In August 2011, the FASB issued ASU No. 2011-08, Intangibles - Goodwill and Other (Topic 350): Testing Goodwill for Impairment. This ASU permits an entity to first assess qualitative factors in determining whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount as a basis for identifying whether it is necessary to perform the two-step goodwill impairment test described in Topic 350. Previous guidance under Topic 350 required an entity to test goodwill for impairment, on at least an annual basis, by comparing the fair value of a reporting unit with its carrying amount, including goodwill (step one). If the fair value of a reporting unit is less than its carrying amount, then the second step of the test must be performed to measure the amount of the impairment loss, if any. Under the amendments in this ASU, an entity is not required to calculate the fair value of a reporting unit unless the entity determines that it is more likely than not that its fair value is less than its carrying amount. This guidance is effective for annual periods for fiscal years ending after December 15, 2011, with early adoption permitted. The adoption of this new guidance did not have a material effect on the Company's consolidated financial statements.

In July 2012, the FASB issued ASU No. 2012-02, Intangibles-Goodwill and Other (Topic 350): Testing Indefinite-Lived Assets for Impairment. This ASU reduces the cost and complexity of performing an impairment test for indefinite-lived intangible assets by simplifying how an entity tests those assets for impairment and to improve consistency in impairment testing guidance among long-lived asset categories. The amendments permit an entity first to assess qualitative factors to determine whether it is more likely than not that an indefinite-lived intangible asset is impaired as a basis for determining whether it is necessary to perform the quantitative impairment test in accordance with Subtopic 350-30, Intangibles - Goodwill and Other - General Intangibles Other than Goodwill. The more-likely-than-not threshold is defined as having a likelihood of more than 50 percent. This guidance is effective for annual and interim impairment tests performed for fiscal years beginning after September 15, 2012. Early adoption is permitted, including for annual and interim impairment tests performed as of a date before July 27, 2012, if a public entity's financial statements for the most recent annual or interim period have not yet been issued or, for nonpublic entities, have not yet been made available for issuance. The adoption of this new guidance did not have a material effect on the Company's consolidated financial statements.

In January 2013, the FASB issued ASU No. 2013-01, Balance Sheet (Topic 210): Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities. This ASU clarifies that the scope of Update 2011-11 applies to derivatives accounted for in accordance with Topic 815, Derivatives and Hedging, including bifurcated embedded derivatives, repurchase agreements and reverse repurchase agreements, and securities borrowing and securities lending transactions that are either offset in accordance with Section 210-20-45 or Section 815-10-45 or subject to an enforceable master netting arrangement or similar agreement. This guidance is effective for fiscal years beginning on or after January 1, 2013, and interim periods within those annual periods. The Company believes the clarifications provided in ASU No. 2013-01 will not have a material effect on the Company's consolidated financial statements.

In February 2013, the FASB issued ASU No. 2013-02, Comprehensive Income (Topic 220): Reporting of Amounts Reclassified out of Accumulated Other Comprehensive Income. This ASU improves the reporting of reclassifications out of accumulated other comprehensive income. The amendments in the ASU seek to attain that objective by requiring an entity to report the effect of significant reclassifications out of accumulated other comprehensive income on the respective line items in net income if the amount being reclassified is required under U.S. generally accepted accounting principles ("GAAP") to be reclassified in its entirety to net income. For other amounts that are not required under GAAP to be reclassified in their entirety to net income in the same reporting period, an entity is required to cross-reference other disclosures required under GAAP that provide additional detail about those amounts. This guidance is effective for reporting periods beginning after December 15, 2012, with early adoption permitted. Other than matters of presentation, the Company believes the adoption of this new guidance will not have a material effect on the Company's consolidated financial statements.