UNAUDITED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS’ EQUITY (Parenthetical) - $ / shares	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Dividends declared per share (in dollars per share)	$ 0.13	$ 0.11	$ 0.25	$ 0.22
Restricted stock, shares cancelled upon vesting for employee withholdings (in shares)			357,305	98,531,000,000
Restricted Stock
Restricted stock, shares cancelled upon forfeitures (in shares)			2,983	0
Restricted Stock \| Cambridge Bancorp
Restricted stock, shares cancelled upon vesting for employee withholdings (in shares)			7,971
Restricted stock, shares cancelled upon forfeitures (in shares)			2,983

Aggregate dividends declared during the period for each share of common stock outstanding.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(03)
-Publisher FASB
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Number of shares used to settle grantee's tax withholding obligation for award under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-4

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