Document and Entity Information [Abstract] Document Information [Table] Legal Entity [Axis] Entity [Domain] Represents the Retirement Plan 002. E B P 002 [Member] Bar Harbor Bankshares 401(k) Plan Document Information [Line Items] Document and Entity Information Document Type Document Period End Date Entity Registrant Name Entity Central Index Key Amendment Flag Statements of Net Assets Available for Benefits EBP, Statement of Net Asset Available for Benefit [Table] EBP, Statement of Net Asset Available for Benefit [Line Items] Statements of Net Assets Available for Benefits EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value Investments, at fair value Fair Value EBP, Note Receivable from Participant Notes receivable from participants EBP, Net Asset Available for Benefit End of year Beginning of year Net assets available for benefits Statement of Changes in Net Assets Available for Benefits EBP, Statement of Change in Net Asset Available for Benefit [Table] EBP, Statement of Change in Net Asset Available for Benefit [Line Items] Statement of Changes in Net Assets Available for Benefits EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment [Abstract] Investment income: EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Unrealized Gain (Loss) on Investment Net appreciation in fair value of investments EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment Interest and dividends from investments EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Other Investment Income (Loss) Other income EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Investment Income (Loss), after Investment Expense Total investment income EBP, Change in Net Asset Available for Benefit, Increase from Interest Income on Note Receivable from Participant Interest on notes receivable from participants EBP, Change in Net Asset Available for Benefit, Increase from Contribution [Abstract] Contributions: EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Excluding Rollover Participants EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash and Noncash Company EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Rollover Rollovers EBP, Change in Net Asset Available for Benefit, Increase from Contribution Total contributions EBP, Change in Net Asset Available for Benefit, Increase Total additions EBP, Change in Net Asset Available for Benefit, Decrease [Abstract] Deductions from net assets attributed to: EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant Benefits paid directly to participants EBP, Change in Net Asset Available for Benefit, Decrease from Administrative Expense Administrative expenses EBP, Change in Net Asset Available for Benefit, Decrease Total deductions EBP, Change in Net Asset Available for Benefit, Increase (Decrease) Net increase in net assets available for benefits EBP, Change in Net Asset Available for Benefit, Increase (Decrease) [Abstract] Net assets available for benefits: Description of Plan EBP, Description of Plan [Table] EBP, Description of Plan [Line Items] Description of Plan EBP, Description of Plan [Text Block] Description of Plan Summary of Significant Accounting Policies EBP, Accounting Policy [Table] EBP, Accounting Policy [Line Items] Summary of Significant Accounting Policies EBP, Summary of Accounting Policy [Text Block] Summary of Significant Accounting Policies Fair Values of Financial Instruments EBP, Investment, Fair Value and NAV [Table] EBP, Investment, Fair Value and NAV [Line Items] Fair Values of Financial Instruments EBP, Investment, Fair Value and NAV [Text Block] Fair Values of Financial Instruments Income Tax Status EBP, Tax Status [Table] EBP, Tax Status [Line Items] Income Tax Status EBP, Tax Status [Text Block] Income Tax Status Related Party and Party-in-Interest Transactions EBP, Related Party and Party-in-Interest Transactions [Table] EBP, Related Party and Party-in-Interest Transactions [Line Items] Related Party and Party-in-Interest Transactions EBP, Related Party and Party-in-Interest Transactions [Text Block] Related Party and Party-in-Interest Transactions Schedule H, Line 4i - Schedule of Assets Held at End of Year EBP, Schedule of Asset Held for Investment [Table] EBP, Schedule of Asset Held for Investment [Line Items] Schedule H, Line 4i - Schedule of Assets Held at End of Year EBP, Schedule of Asset Held for Investment [Text Block] Schedule H, Line 4i - Schedule of Assets Held at End of Year EBP, Basis of Accounting [Policy Text Block] Basis of Presentation EBP, Investment [Policy Text Block] Investment Valuation and Income Recognition EBP, Note Receivable from Participant [Policy Text Block] Notes Receivable EBP, Contribution [Policy Text Block] Contributions EBP, Payment to Participant [Policy Text Block] Payment of Benefits EBP, Expense [Policy Text Block] Expenses EBP, Use of Estimate [Policy Text Block] Use of Estimates EBP, Risk and Uncertainty [Policy Text Block] Risks and Uncertainties EBP, Subsequent Event [Policy Text Block] Subsequent Events EBP, Investment, Fair Value and NAV [Table Text Block] Schedule of plan's investment assets at fair value Disclosure of investments whose fair value is estimated using net asset value (NAV) per share (or its equivalent), including related information such as fair value, unfunded commitments, redemption frequency, redemption notice periods, and other terms and conditions associated with the investments. Employee Benefit Plan, Investment, Fair Value Estimated Using NAV Per Share [Table Text Block] Schedule of Plan's investments whose fair value is estimated using NAV per share Scenario [Axis] Scenario [Domain] Member representing the first tier of participant contributions under the employee benefit plan matching contribution formula to which a specified employer matching contribution percentage applies. Employee Benefit Plan, Matching Contribution, First Tier [Member] First Tier Member representing the second tier of participant contributions under the employee benefit plan matching contribution formula to which a specified employer matching contribution percentage applies. Employee Benefit Plan, Matching Contribution, Second Tier [Member] Second Tier Statistical Measurement [Axis] Statistical Measurement [Domain] Minimum [Member] Minimum Maximum [Member] Maximum Represents the minimum age criteria for plan eligibility under employee benefit plan. Employee Benefit Plan, Minimum Age For Plan Eligibility Minimum age for Plan eligibility Represents the minimum service period for plan eligibility under employee benefit plan EBP. Employee Benefit Plan, Minimum Service Period For Plan Eligibility Minimum service period for Plan eligibility EBP, Participant Contribution, Pretax, Maximum Annual Compensation to Total Compensation, Percentage Employee contribution Age specified by the employee benefit plan at which participants become eligible to make catch-up contributions under applicable plan provisions and statutory requirements. Employee Benefit Plan,. Catch-up Contribution Eligibility Age Age for contribution eligibility EBP, Participant Contribution, Automatic, Deferral Rate Participants automatic deferral rate (in %) Percentage increase in the automatic deferral rate applied annually to eligible compensation for participants automatically enrolled in an employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Employee Benefit Plan, Participant Annual Contribution Increase Rate, Percentage Annual automatic deferral increase rate (in %) EBP, Employer Contribution, Matching Percentage Employer matching contribution (as a percent) EBP, Employer Contribution, Participant Compensation Matched, Percentage Participant compensation matched (as a percent) Represents the percentage of vesting. Employee Benefit Plan, Vesting Percentage Vesting percentage Represents the percentage of vesting of participant accounts in the event of termination. Employee Benefit Plan, Vesting Percentage in Event of Termination Vesting percentage, in the event of plan termination Represents the participant age requirement for withdrawal from account balance of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Employee Benefit Plan, Participant Age For Withdrawal From Account Balance Threshold age for withdrawal EBP, Note Receivable from Participant, Account, Maximum Borrowing, Amount Note receivable, maximum borrowing amount Represents the percentage points added to the prime rate to compute the interest rate on participant loans. Employee Benefit Plan, Note Receivable From Participant, Basis Spread on Prime Rate Note receivable, interest spread rate over the Prime Rate (%) EBP, Note Receivable from Participant, Account, Maximum Borrowing, to Total Account, Percentage Note receivable, loan interest rate (%) EBP, Asset Held for Investment, Participant Loan, Interest Rate Loan interest rate Term of participant loan of employee stock purchase, saving, or similar plan employee benefit plan EBP. Employee Benefit Plan, Note Receivable From Participant, Term Loan term EBP, Note Receivable from Participant, Allowance for Credit Loss Allowance for credit loss Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] Fair Value, Level 1, Level 2, and Level 3 Fair Value, Inputs, Level 1 [Member] Level 1 Fair Value Measured at Net Asset Value Per Share [Member] Net Asset Value Investment Type [Axis] Investments [Domain] Mutual Fund [Member] Mutual funds EBP, Employer, Common Stock [Member] Common Stock of BHB Common Collective Trust [Member] Common Collective Trust EBP, Tax Determination Letter, Obtained [true false] Determination letter obtained EBP, Tax Determination Letter, Date Determination letter date EBP, Tax Qualification Status [Extensible Enumeration] Tax qualification status EBP, Related Party and Party-in-Interest [Axis] EBP, Related Party and Party-in-Interest [Domain] Employer of participant in employee stock purchase, saving, or similar plan employee benefit plan EBP. Employee Benefit Plan, Employer [Member] Company Represents the information pertaining to Morgan Stanley. Morgan Stanley [Member] Morgan Stanley EBP, Investment, Number of Shares Number of shares held EBP, Investment Acquired, Excluding Plan Interest in Master Trust, Cost Purchases of investment EBP, Investment Sold, Excluding Plan Interest in Master Trust, Selling Price Sale of investment EBP, Change in Net Asset Available for Benefit, Increase from Dividend Income on Investment Dividend income Amount of investment advisory services fee incurred by employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Employee Benefit Plan, Investment Advisory Services Fee Investment advisory services cost Investment, Identifier [Axis] Entity Tax Identification Number Entity tax identification number EBP, Plan Number Plan number EBP, Investment, Issuer Name [Extensible Enumeration] Investment issuer name EBP, Investment, Current Value, Type [Extensible Enumeration] Investment type EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Current Value Current Value EBP, Asset Held for Investment, Participant Loan, after Deemed Distribution Participant loans EBP, Asset Held for Investment Total EBP, Asset Held for Investment, Party-in-Interest [true false] Investment party in interest EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration]