Cover - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2020	Feb. 17, 2021	Jun. 30, 2020
Cover [Abstract]
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	001-34223
Entity Registrant Name	CLEAN HARBORS, INC
Entity Incorporation, State or Country Code	MA
Entity Tax Identification Number	04-2997780
Entity Address, Address Line One	42 Longwater Drive
Entity Address, City or Town	Norwell
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02061-9149
City Area Code	781
Local Phone Number	792-5000
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	CLH
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
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 3.1
Entity Common Stock, Shares Outstanding		54,796,559
Documents Incorporated by Reference	Certain portions of the registrant's definitive proxy statement for its 2021 annual meeting of stockholders (which will be filed with the Commission not later than April 23, 2021) are incorporated by reference into Part III of this report.
Entity Central Index Key	0000822818
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false