v3.25.1
Document and Entity Information - USD ($)
 12 Months Ended
Mar. 31, 2025
May 09, 2025
Sep. 30, 2024
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Mar. 31, 2025    
Current Fiscal Year End Date --03-31    
Document Transition Report false    
Entity File Number 001-32312    
Entity Registrant Name Novelis Inc.    
Entity Incorporation, State or Country Code Z4    
Entity Tax Identification Number 98-0442987    
Entity Address, Address Line One 3550 Peachtree Road NE, Suite 1100    
Entity Address, City or Town Atlanta    
Entity Address, State or Province GA    
Entity Address, Postal Zip Code 30326    
City Area Code (404)    
Local Phone Number 760-4000    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers Yes    
Entity Current Reporting Status No    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag false    
Document Financial Statement Error Correction false    
Entity Shell Company false    
Entity Public Float     $ 0
Entity Common Stock, Shares Outstanding   600,000,000  
Documents Incorporated by Reference None    
Entity Central Index Key 0001304280    
Amendment Flag false    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY