Annual report pursuant to Section 13 and 15(d)

Document and Entity Information

Document and Entity Information - USD ($)
12 Months Ended
May 31, 2017
Jun. 30, 2017
Nov. 30, 2016
Document and Entity Information [Abstract]      
Entity Registrant Name PAYCHEX INC    
Entity Filer Category Large Accelerated Filer    
Entity Central Index Key 0000723531    
Entity Well-known Seasoned Issuer Yes    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Amendment Flag false    
Document Type 10-K    
Trading Symbol PAYX    
Document Fiscal Period Focus FY    
Document Period End Date May 31, 2017    
Document Fiscal Year Focus 2017    
Current Fiscal Year End Date --05-31    
Entity Common Stock, Shares Outstanding   359,395,731  
Entity Public Float     $ 18,874,963,639