v3.26.1
Document and Entity Information - USD ($)
 12 Months Ended
Mar. 31, 2026
Sep. 30, 2025
Cover [Abstract]    
Entity Registrant Name Orion Energy Systems, Inc.  
Entity Central Index Key 0001409375  
Document Type 10-K  
Document Period End Date Mar. 31, 2026  
Document Financial Statement Error Correction [Flag] false  
Amendment Flag false  
Document Fiscal Year Focus 2026  
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 Shell Company false  
Entity Emerging Growth Company false  
Entity Small Business true  
Entity File Number 001-33887  
Entity Tax Identification Number 39-1847269  
Entity Address, Address Line One 2210 Woodland Drive  
Entity Address, City or Town Manitowoc  
Entity Address, State or Province WI  
Entity Address, Postal Zip Code 54220  
City Area Code 920  
Local Phone Number 892-9340  
Entity Interactive Data Current Yes  
Entity Incorporation, State or Country Code WI  
ICFR Auditor Attestation Flag false  
Document Annual Report true  
Document Transition Report false  
Title of 12(b) Security Common stock, no par value  
Trading Symbol OESX  
Security Exchange Name NASDAQ  
Auditor Name BDO USA, P.C.  
Auditor Location Milwaukee, WI  
Auditor Firm ID 243  
Entity Public Float   $ 734,234
Documents Incorporated by Reference

Portions of the Registrant's Proxy Statement for the 2026 Annual Meeting of Shareholders to be held on August 6, 2026 are incorporated herein by reference in Part III of this Annual Report on Form 10-K.