v3.26.1
Financial instruments and Retirement benefit obligations - Financial instruments - Carrying amounts and fair values (Details) - USD ($)
$ in Millions
Jun. 27, 2026
Dec. 31, 2025
Jun. 28, 2025
Disclosure of detailed information about financial instruments [line items]      
Financial assets $ 2,323 $ 2,017 $ 2,034
Financial liabilities (5,094) (4,478) (4,439)
At fair value      
Disclosure of detailed information about financial instruments [line items]      
Financial assets 215 182 62
Financial assets, at fair value 215 182 62
Financial liabilities (298) (124) (125)
Financial liabilities, at fair value (298) (124) (125)
At fair value | Acquisition consideration      
Disclosure of detailed information about financial instruments [line items]      
Financial liabilities (286) (107) (89)
At fair value | Acquisition consideration | Level 3      
Disclosure of detailed information about financial instruments [line items]      
Financial liabilities, at fair value (286) (107) (89)
At fair value | Forward foreign exchange contracts      
Disclosure of detailed information about financial instruments [line items]      
Financial liabilities (8) (15) (36)
At fair value | Forward foreign exchange contracts | Level 2      
Disclosure of detailed information about financial instruments [line items]      
Financial liabilities, at fair value (8) (15) (36)
At fair value | Interest rate swaps      
Disclosure of detailed information about financial instruments [line items]      
Financial liabilities (3)    
At fair value | Interest rate swaps | Level 2      
Disclosure of detailed information about financial instruments [line items]      
Financial liabilities, at fair value (3)    
At fair value | Currency swaps      
Disclosure of detailed information about financial instruments [line items]      
Financial liabilities (1) (2)  
At fair value | Currency swaps | Level 2      
Disclosure of detailed information about financial instruments [line items]      
Financial liabilities, at fair value (1) (2)  
At fair value | Forward foreign exchange contracts      
Disclosure of detailed information about financial instruments [line items]      
Financial assets 54 33 2
At fair value | Forward foreign exchange contracts | Level 2      
Disclosure of detailed information about financial instruments [line items]      
Financial assets, at fair value 54 33 2
At fair value | Investments.      
Disclosure of detailed information about financial instruments [line items]      
Financial assets 25 30 29
At fair value | Investments. | Level 1 & 3      
Disclosure of detailed information about financial instruments [line items]      
Financial assets, at fair value 25 30 29
At fair value | Investments relating to deferred compensation arrangements      
Disclosure of detailed information about financial instruments [line items]      
Financial assets 120 106  
At fair value | Investments relating to deferred compensation arrangements | Level 1      
Disclosure of detailed information about financial instruments [line items]      
Financial assets, at fair value 120 106  
At fair value | Interest rate swaps      
Disclosure of detailed information about financial instruments [line items]      
Financial assets 15 11 31
At fair value | Interest rate swaps | Level 2      
Disclosure of detailed information about financial instruments [line items]      
Financial assets, at fair value 15 11 31
At fair value | Currency swaps      
Disclosure of detailed information about financial instruments [line items]      
Financial assets 1 2  
At fair value | Currency swaps | Level 2      
Disclosure of detailed information about financial instruments [line items]      
Financial assets, at fair value 1 2  
Not measured at fair value      
Disclosure of detailed information about financial instruments [line items]      
Financial assets 2,108 1,835 1,972
Financial liabilities (4,796) (4,354) (4,314)
Not measured at fair value | Acquisition consideration      
Disclosure of detailed information about financial instruments [line items]      
Financial liabilities     (9)
Not measured at fair value | Bank overdraft and loans      
Disclosure of detailed information about financial instruments [line items]      
Financial liabilities (19) (8) (17)
Not measured at fair value | Corporate bond not in a hedge relationship      
Disclosure of detailed information about financial instruments [line items]      
Financial liabilities (1,395) (1,394) (1,493)
Not measured at fair value | Corporate bond in a hedge relationship      
Disclosure of detailed information about financial instruments [line items]      
Financial liabilities (1,624) (1,084) (1,110)
Not measured at fair value | Private placement debt not in a hedge relationship      
Disclosure of detailed information about financial instruments [line items]      
Financial liabilities (550) (625) (625)
Not measured at fair value | Trade and other payables      
Disclosure of detailed information about financial instruments [line items]      
Financial liabilities (1,208) (1,243) (1,060)
Not measured at fair value | Trade and other receivables.      
Disclosure of detailed information about financial instruments [line items]      
Financial assets 1,354 1,278 1,296
Not measured at fair value | Cash and cash equivalents      
Disclosure of detailed information about financial instruments [line items]      
Financial assets $ 754 $ 557 $ 676