v3.26.1
Financial instruments and Retirement benefit obligations - Financial instruments - Transfers (Details) - USD ($)
$ in Millions
1 Months Ended 6 Months Ended 12 Months Ended
Jan. 31, 2026
Jun. 27, 2026
Dec. 31, 2025
Disclosure of detailed information about financial instruments [line items]      
Transfer from Level 1 to Level 2 assets   $ 0 $ 0
Transfer from Level 2 to Level 1 assets   0 0
Transfer from Level 1 to Level 2 liabilities   0 0
Transfer from Level 2 to Level 1 liabilities   $ 0 0
Transfer into Level 3 assets     0
Transfer out of Level 3 assets     0
Transfer into Level 3 liabilities     0
Transfer out of Level 3 liabilities     $ 0
Investments.      
Disclosure of detailed information about financial instruments [line items]      
Transfer out of Level 3 assets $ 20