v3.19.1
Document and Entity Information - USD ($)
12 Months Ended
Mar. 31, 2019
May 31, 2019
Sep. 30, 2018
Document And Entity Information [Abstract]      
Entity Registrant Name ORION ENERGY SYSTEMS, INC.    
Entity Central Index Key 0001409375    
Trading Symbol OESX    
Document Type 10-K    
Document Period End Date Mar. 31, 2019    
Amendment Flag false    
Document Fiscal Year Focus 2019    
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 Non-accelerated Filer    
Entity Emerging Growth Company false    
Entity Small Business true    
Entity Shell Company false    
Entity Public Float     $ 19,881,105
Entity Common Stock, Shares Outstanding   29,601,669