v3.26.1
Asbestos - Schedule of Net Unfunded AFFA Liability, Net of Tax (Details)
$ in Millions, $ in Millions
 12 Months Ended
Mar. 31, 2026
USD ($)
Mar. 31, 2026
AUD ($)
Mar. 31, 2025
USD ($)
Mar. 31, 2025
AUD ($)
Mar. 31, 2024
USD ($)
Mar. 31, 2024
AUD ($)
Asbestos Net Liability [Roll Forward]            
Change in claims handling cost estimate $ (0.8)   $ 0.5   $ (8.5)  
Net Unfunded AFFA Liability, net of tax            
Asbestos Net Liability [Roll Forward]            
Net Unfunded AFFA liability, net of tax, Beginning Balance (418.1)          
Asbestos claims paid 0.0          
Payment received in accordance with AFFA 125.4          
AICF claims-handling costs incurred (paid) 0.0          
AICF operating costs paid - non claims-handling (1.9)          
Change in actuarial estimate (49.7)          
Change in claims handling cost estimate (0.8)          
Impact on deferred income tax due to change in actuarial estimate 15.2          
Insurance recoveries 0.0          
Movement in income tax payable (38.7)          
Other movements 14.6          
Effect of foreign exchange (38.7)          
Net Unfunded AFFA liability, net of tax, Ending Balance (392.7)   (418.1)      
Deferred Tax Assets            
Asbestos Net Liability [Roll Forward]            
Asbestos, deferred tax assets, beginning balance 282.5   284.5      
Impact on deferred income tax due to change in actuarial estimate 15.2          
Movement in income tax payable (38.5)          
Other movements (2.9)          
Effect of foreign exchange 24.2          
Asbestos, deferred tax assets, beginning balance 282.5   284.5      
Income Tax Payable            
Asbestos Net Liability [Roll Forward]            
Asbestos, income tax payable, beginning balance 37.9          
Movement in income tax payable (0.2)          
Other movements 0.4          
Effect of foreign exchange 2.1          
Asbestos, income tax payable, ending balance 40.2   37.9      
Net Unfunded AFFA Liability            
Asbestos Net Liability [Roll Forward]            
Asbestos, net liability, beginning balance (740.5)          
Payment received in accordance with AFFA 125.4          
AICF operating costs paid - non claims-handling (1.9)          
Change in actuarial estimate (49.7)          
Change in claims handling cost estimate (0.8)          
Other movements 17.1          
Effect of foreign exchange (65.0)          
Asbestos net liability, ending balance (715.4)   (740.5)      
Asbestos Liability            
Asbestos Net Liability [Roll Forward]            
Asbestos, net liability, beginning balance (983.6)          
Asbestos claims paid 105.4          
AICF claims-handling costs incurred (paid) 1.6          
Change in actuarial estimate (46.7)          
Change in claims handling cost estimate (0.8)          
Effect of foreign exchange (84.5)          
Asbestos net liability, ending balance (1,008.6)   (983.6)      
Insurance Receivables            
Asbestos Net Liability [Roll Forward]            
Asbestos, net liability, beginning balance 28.7          
Change in actuarial estimate (3.0)          
Insurance recoveries (3.8)          
Effect of foreign exchange 2.4          
Asbestos net liability, ending balance 24.3   28.7      
Restricted Cash and Investments            
Asbestos Net Liability [Roll Forward]            
Asbestos, net liability, beginning balance 213.7          
Asbestos claims paid (105.4)          
Payment received in accordance with AFFA 125.4 $ 193.6 99.2 $ 149.6 $ 91.8 $ 137.5
AICF claims-handling costs incurred (paid) (1.6)          
AICF operating costs paid - non claims-handling (1.9)          
Insurance recoveries 3.8          
Other movements 17.6          
Effect of foreign exchange 17.1          
Asbestos net liability, ending balance 268.7   213.7      
Other Assets and Liabilities            
Asbestos Net Liability [Roll Forward]            
Asbestos, net liability, beginning balance 0.7          
Other movements (0.5)          
Asbestos net liability, ending balance $ 0.2   $ 0.7