Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 22, 2021	Jun. 30, 2020
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	0-28190
Entity Registrant Name	CAMDEN NATIONAL CORP
Entity Incorporation, State or Country Code	ME
Entity Tax Identification Number	01-0413282
Entity Address, Postal Zip Code	04843
Entity Address, Address Line One	2 Elm Street
Entity Address, City or Town	Camden
Entity Address, State or Province	ME
City Area Code	207
Local Phone Number	236-8821
Title of 12(b) Security	Common Stock, without par value
Trading Symbol	CAC
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 507,543,246
Entity Common Stock, Shares Outstanding		14,913,098
Documents Incorporated by Reference	Certain information required in response to Items 10, 11, 12, 13 and 14 of Part III of this Form 10-K is incorporated by reference from Camden National Corporation’s Definitive Proxy Statement for the 2021 Annual Meeting of Shareholders pursuant to Regulation 14A of the General Rules and Regulations of the Commission.
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Central Index Key	0000750686