Document and Entity Information - shares
3 Months Ended
Sep. 30, 2019
Oct. 22, 2019
Document and Entity Information    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Sep. 30, 2019  
Document Transition Report false  
Entity File Number 000-23125  
Entity Registrant Name OSI SYSTEMS, INC.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 33-0238801  
Entity Address, Address Line One 12525 Chadron Avenue  
Entity Address, City or Town Hawthorne  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 90250  
City Area Code (310)  
Local Phone Number 978-0516  
Title of 12(b) Security Common Stock  
Trading Symbol true  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Filer Category Large Accelerated Filer  
Entity Interactive Data Current Yes  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   18,357,463
Entity Central Index Key 0001039065  
Current Fiscal Year End Date --06-30  
Document Fiscal Year Focus 2020  
Document Fiscal Period Focus Q1  
Amendment Flag false