v3.26.1
Cover Page - USD ($)
$ in Billions
12 Months Ended
Jun. 30, 2026
Aug. 14, 2026
Jul. 31, 2026
Dec. 31, 2025
Entity Information [Line Items]        
Document Type 10-K      
Document Annual Report true      
Document Period End Date Jun. 30, 2026      
Current Fiscal Year End Date --06-30      
Document Transition Report false      
Entity File Number 001-41072      
Registrant Name IREN Limited      
Entity Incorporation, State or Country Code C3      
Entity Address, Address Line One Level 5, 55 Market Street      
Entity Address, City or Town Sydney      
Entity Address, Country AU      
Entity Address, Postal Zip Code 2000      
City Area Code 61 2      
Local Phone Number 7906 8301      
Title of 12(b) Security Ordinary shares, no par value      
Trading Symbol IREN      
Security Exchange Name NASDAQ      
Entity Well-known Seasoned Issuer Yes      
Entity Voluntary Filers No      
Entity Current Reporting Status Yes      
Entity Interactive Data Current Yes      
Entity Filer Category Large Accelerated Filer      
Entity Small Business false      
Entity Emerging Growth Company false      
ICFR Auditor Attestation Flag true      
Document Financial Statement Error Correction [Flag] true      
Document Financial Statement Restatement Recovery Analysis [Flag] false      
Entity Shell Company false      
Entity Public Float       $ 11.9
Central Index Key 0001878848      
Amendment Flag false      
Document Fiscal Year Focus 2026      
Document Fiscal Period Focus FY      
Class A common stock        
Entity Information [Line Items]        
Entity Common Stock, Shares Outstanding   394,058,648    
Class B common stock        
Entity Information [Line Items]        
Entity Common Stock, Shares Outstanding     2