Fair Values of Financial Instruments - Fair value estimated using NAV per share (Details) - Bar Harbor Bankshares 401(k) Plan - USD ($)	Dec. 31, 2025	Dec. 31, 2024
Fair Values of Financial Instruments
Fair Value	$ 72,936,966	$ 62,114,885
Common Collective Trust
Fair Values of Financial Instruments
Fair Value	$ 1,697,248	$ 2,027,315

Fair value of investment, excluding plan interest in master trust, held by employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Includes, but is not limited to, derivative, investment measured at net asset value per share as practical expedient, and insurance contract not meeting fully-benefit responsive investment criteria.

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+ Details

- 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.

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