v3.5.0.1
Document and Entity Information - USD ($)
12 Months Ended
Mar. 31, 2016
Jun. 09, 2016
Sep. 30, 2015
Document and Entity Information [Abstract]      
Entity Registrant Name ORION ENERGY SYSTEMS, INC.    
Entity Central Index Key 0001409375    
Document Type 10-K    
Document Period End Date Mar. 31, 2016    
Amendment Flag false    
Document Fiscal Year Focus 2016    
Document Fiscal Period Focus FY    
Current Fiscal Year End Date --03-31    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Filer Category Smaller Reporting Company    
Entity Public Float     $ 40,265,665
Entity Common Stock, Shares Outstanding   28,059,351