Document and Entity Information - USD ($)
 12 Months Ended
Mar. 31, 2020
May 22, 2020
Sep. 30, 2019
DEI [Abstract]      
Title of 12(b) Security Ordinary Shares, $0.001 par value    
Entity Incorporation, State or Country Code L2    
Document Transition Report false    
Document Annual Report true    
Entity Registrant Name STERIS plc    
Entity Central Index Key 0001757898    
Entity Shell Company false    
Document Type 10-K    
Document Period End Date Mar. 31, 2020    
Entity File Number 001-38848    
Amendment Flag false    
Document Fiscal Year Focus 2020    
Document Fiscal Period Focus FY    
Current Fiscal Year End Date --03-31    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Common Stock, Shares Outstanding   84,918,305  
Entity Well-known Seasoned Issuer Yes    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Public Float     $ 12,164,200,000
Entity Voluntary Filers No    
Entity Tax Identification Number 98-1455064    
Entity Address, Address Line One 70 Sir John Rogerson's Quay,    
Entity Address, City or Town Dublin 2,    
Entity Address, Country IE    
Entity Address, Postal Zip Code D02 R296    
Trading Symbol STE    
Security Exchange Name NYSE    
Country Region 353    
City Area Code 1    
Local Phone Number 232 2000    
Filed report attestation on section 404(b) Sarbanes-Oxley Act Yes