v3.26.3
Cover Page - shares
 3 Months Ended
Sep. 30, 2026
Oct. 30, 2026
Document Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Sep. 30, 2026  
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 Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Central Index Key 0001878848  
Amendment Flag false  
Current Fiscal Year End Date --06-30  
Document Fiscal Year Focus 2027  
Document Fiscal Period Focus Q1  
Common Class A    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   424,357,381
Common Class B    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   2