v3.26.1
Debt (Redemption and retirement) (Details) - USD ($)
$ in Millions
1 Months Ended 3 Months Ended 12 Months Ended
Mar. 31, 2026
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2026
Debt        
Repayments of debt   $ 556 $ 210  
Loss on retirement of debt   $ (11)    
8.375% Senior Secured Notes due February 2028        
Debt        
Repayments of debt $ 365      
Scheduled installment $ 67      
Debt instrument interest rate stated percentage 8.375% 8.375%    
Aggregate principal amount of debt retired $ 358      
Loss on retirement of debt       $ (11)