Document and Entity Information - shares
9 Months Ended
Mar. 31, 2018
Apr. 27, 2018
Document and Entity Information    
Entity Registrant Name OSI SYSTEMS INC  
Entity Central Index Key 0001039065  
Document Type 10-Q  
Document Period End Date Mar. 31, 2018  
Amendment Flag false  
Current Fiscal Year End Date --06-30  
Entity Current Reporting Status Yes  
Entity Filer Category Large Accelerated Filer  
Entity Common Stock, Shares Outstanding   18,072,644
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q3