Cover - shares	9 Months Ended
	Sep. 30, 2021	Oct. 29, 2021
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	0-28190
Entity Registrant Name	CAMDEN NATIONAL CORP
Entity Central Index Key	0000750686
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Incorporation, State or Country Code	ME
Entity Tax Identification Number	01-0413282
Entity Address, Address Line One	2 ELM STREET
Entity Address, City or Town	CAMDEN
Entity Address, State or Province	ME
Entity Address, Postal Zip Code	04843
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 Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		14,849,347