Fair value measurements - Financial Assets and Liabilities at Fair Value (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 28, 2025	Sep. 29, 2024	Dec. 29, 2024
Financial assets and liabilities at fair value
Derivatives designated as hedging instruments : Assets	$ 1,404
Derivatives designated as hedging instruments : Liabilities	6,065
Available-for-sale Securities, Equity Securities	573		$ 451
Available-for-sale Securities	3,825		7,216
Contingent consideration	1,110		1,217
Total Gross Assets	1,445		2,194
Credit Support Agreement (CSA)	(1,238)		(2,172)
Total Net Asset	207		22
Total Gross Liabilities	6,093		4,564
Credit Support Agreement (CSA)	(6,062)		(4,412)
Total Net Liabilities	31		152
Beginning Balance	1,217	$ 1,092
Changes in estimated fair value(6)	(57)	93
Additions	0	112
Payments	(50)	(75)
Ending Balance	1,110	$ 1,222
Quoted prices in active markets for identical assets and liabilities Level 1
Financial assets and liabilities at fair value
Derivatives designated as hedging instruments : Assets	0
Derivatives designated as hedging instruments : Liabilities	0
Available-for-sale Securities, Equity Securities	573		451
Available-for-sale Securities	0
Contingent consideration	0
Significant other observable inputs Level 2
Financial assets and liabilities at fair value
Derivatives designated as hedging instruments : Assets	1,404		2,144
Derivatives designated as hedging instruments : Liabilities	6,065		4,547
Available-for-sale Securities, Equity Securities	0
Available-for-sale Securities	3,825
Contingent consideration	0
Significant unobservable inputs Level 3
Financial assets and liabilities at fair value
Derivatives designated as hedging instruments : Assets	0
Derivatives designated as hedging instruments : Liabilities	0
Available-for-sale Securities, Equity Securities	0
Available-for-sale Securities	0
Contingent consideration	1,110		1,217
Interest Rate Contract
Financial assets and liabilities at fair value
Derivatives designated as hedging instruments : Assets	589
Derivatives designated as hedging instruments : Liabilities	5,695
Interest Rate Contract | Quoted prices in active markets for identical assets and liabilities Level 1
Financial assets and liabilities at fair value
Derivatives designated as hedging instruments : Assets	0
Derivatives designated as hedging instruments : Liabilities	0
Interest Rate Contract | Significant other observable inputs Level 2
Financial assets and liabilities at fair value
Derivatives designated as hedging instruments : Assets	589		1,484
Derivatives designated as hedging instruments : Liabilities	5,695		3,753
Interest Rate Contract | Significant unobservable inputs Level 3
Financial assets and liabilities at fair value
Derivatives designated as hedging instruments : Assets	0
Derivatives designated as hedging instruments : Liabilities	0
Forward foreign exchange contracts
Financial assets and liabilities at fair value
Derivatives designated as hedging instruments : Assets	815
Derivatives designated as hedging instruments : Liabilities	370
Derivatives not designated as hedging instruments : Assets	41
Derivatives not designated as hedging instruments : Liabilities	28
Forward foreign exchange contracts | Quoted prices in active markets for identical assets and liabilities Level 1
Financial assets and liabilities at fair value
Derivatives designated as hedging instruments : Assets	0
Derivatives designated as hedging instruments : Liabilities	0
Derivatives not designated as hedging instruments : Assets	0
Derivatives not designated as hedging instruments : Liabilities	0
Forward foreign exchange contracts | Significant other observable inputs Level 2
Financial assets and liabilities at fair value
Derivatives designated as hedging instruments : Assets	815		660
Derivatives designated as hedging instruments : Liabilities	370		794
Derivatives not designated as hedging instruments : Assets	41		50
Derivatives not designated as hedging instruments : Liabilities	28		$ 17
Forward foreign exchange contracts | Significant unobservable inputs Level 3
Financial assets and liabilities at fair value
Derivatives designated as hedging instruments : Assets	0
Derivatives designated as hedging instruments : Liabilities	0
Derivatives not designated as hedging instruments : Assets	0
Derivatives not designated as hedging instruments : Liabilities	$ 0