Cover Page - USD ($)	12 Months Ended
	Dec. 25, 2021	Jan. 21, 2022	Jun. 26, 2021
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 25, 2021
Current Fiscal Year End Date	--12-25
Document Transition Report	false
Entity File Number	001-15943
Entity Registrant Name	CHARLES RIVER LABORATORIES INTERNATIONAL, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	06-1397316
Entity Address, Address Line One	251 Ballardvale Street
Entity Address, City or Town	Wilmington
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01887
City Area Code	781
Local Phone Number	222-6000
Title of 12(b) Security	Common stock, $0.01 par value
Trading Symbol	CRL
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Smaller Reporting Company	false
Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 18,338,961,840
Entity Common Stock, Shares Outstanding		50,486,047
Documents Incorporated by Reference	Portions of the registrant’s definitive Proxy Statement for its 2022 Annual Meeting of Shareholders scheduled to be held on May 10, 2022, which will be filed with the Securities and Exchange Commission (SEC) not later than 120 days after December 25, 2021, are incorporated by reference into Part III of this Annual Report on Form 10-K. With the exception of the portions of the 2022 Proxy Statement expressly incorporated into this Annual Report on Form 10-K by reference, such document shall not be deemed filed as part of this Form 10-K.
Entity Central Index Key	0001100682
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Amendment Flag	false