Shareholders' Equity

9 Months Ended

Sep. 30, 2023

Equity [Abstract]

Shareholders' Equity

13. Shareholders’ Equity

As of September 30, 2023 and December 31, 2022, the Company and the Bank met all applicable minimum capital requirements and were considered “well-capitalized” by both the Federal Reserve Bank (“FRB”) and the Federal Deposit Insurance Corporation (“FDIC”).

	Actual					Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer					Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions
	Amount		Ratio			Amount		Ratio			Amount		Ratio
	(dollars in thousands)
At September 30, 2023
Cambridge Bancorp:
Total capital (to risk-weighted assets)	$	518,398		14.2	%	$	383,672		10.5	%	N/A		N/A
Tier 1 capital (to risk-weighted assets)		478,273		13.1	%		310,591		8.5	%	N/A		N/A
Common equity tier I capital (to risk-weighted assets)		478,273		13.1	%		255,781		7.0	%	N/A		N/A
Tier 1 capital (to average assets)		478,273		8.8	%		216,714		4.0	%	N/A		N/A
Cambridge Trust Company:
Total capital (to risk-weighted assets)	$	496,819		13.6	%	$	383,636		10.5	%	$	365,368		10.0	%
Tier 1 capital (to risk-weighted assets)		456,694		12.5	%		310,563		8.5	%		292,294		8.0	%
Common equity tier I capital (to risk-weighted assets)		456,694		12.5	%		255,757		7.0	%		237,489		6.5	%
Tier 1 capital (to average assets)		456,694		8.4	%		216,700		4.0	%		270,875		5.0	%

	Actual					Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer					Minimum To Be Well-Capitalized Under Prompt Corrective Action Provisions
	Amount		Ratio			Amount		Ratio			Amount		Ratio
	(dollars in thousands)
At December 31, 2022
Cambridge Bancorp:
Total capital (to risk-weighted assets)	$	506,239		13.5	%	$	393,285		10.5	%	N/A		N/A
Tier 1 capital (to risk-weighted assets)		466,369		12.5	%		318,373		8.5	%	N/A		N/A
Common equity tier I capital (to risk-weighted assets)		466,369		12.5	%		262,190		7.0	%	N/A		N/A
Tier 1 capital (to average assets)		466,369		8.5	%		219,309		4.0	%	N/A		N/A
Cambridge Trust Company:
Total capital (to risk-weighted assets)	$	490,175		13.1	%	$	393,246		10.5	%	$	374,520		10.0	%
Tier 1 capital (to risk-weighted assets)		450,305		12.0	%		318,342		8.5	%		299,616		8.0	%
Common equity tier I capital (to risk-weighted assets)		450,305		12.0	%		262,164		7.0	%		243,438		6.5	%
Tier 1 capital (to average assets)		450,305		8.2	%		219,296		4.0	%		274,120		5.0	%