Document and Entity Information - shares	3 Months Ended
	Aug. 31, 2018	Sep. 30, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	PAYCHEX INC
Entity Filer Category	Large Accelerated Filer
Entity Central Index Key	0000723531
Entity Small Business	false
Entity Emerging Growth Company	false
Amendment Flag	false
Document Type	10-Q
Trading Symbol	PAYX
Document Fiscal Period Focus	Q1
Document Period End Date	Aug. 31, 2018
Document Fiscal Year Focus	2019
Current Fiscal Year End Date	--05-31
Entity Common Stock, Shares Outstanding		359,081,940