Document and Entity Information - shares	9 Months Ended
	Feb. 28, 2018	Mar. 31, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	CINTAS CORP
Entity Central Index Key	0000723254
Document Type	10-Q
Document Period End Date	Feb. 28, 2018
Amendment Flag	false
Current Fiscal Year End Date	--05-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		106,720,902
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q3