Cover - USD ($)	12 Months Ended
	May 31, 2020	Jun. 30, 2020	Nov. 29, 2019
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Period End Date	May 31, 2020
Document Transition Report	false
Entity File Number	0-11399
Entity Registrant Name	Cintas Corp
Entity Central Index Key	0000723254
Current Fiscal Year End Date	--05-31
Document Fiscal Year Focus	2020
Entity Incorporation, State or Country Code	WA
Entity Tax Identification Number	31-1188630
Document Fiscal Period Focus	FY
Entity Address, Address Line One	6800 Cintas Boulevard
Entity Address, Address Line Two	P.O. Box 625737
Entity Address, City or Town	Cincinnati,
Entity Address, State or Province	OH
Entity Address, Postal Zip Code	45262-5737
City Area Code	(513)
Local Phone Number	459-1200
Title of 12(b) Security	Common stock, no par value
Trading Symbol	CTAS
Security Exchange Name	NASDAQ
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			$ 26,657,809,636
Entity Common Stock, Shares Outstanding		103,499,012
Documents Incorporated by Reference	Portions of the Registrant's Proxy Statement to be filed with the Commission for its 2020 Annual Meeting of Shareholders are incorporated by reference in Part III of this Form 10-K.