Income taxes - Summary of Activity Related to Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Jan. 01, 2023	Jan. 02, 2022
Summary of unrecognized tax benefits
Beginning of year	$ 3,716	$ 3,210	$ 3,260
Increases related to current year tax positions	239	523	242
Increases related to prior period tax positions	244	143	23
Decreases related to prior period tax positions	(781)	(148)	(128)
Settlements	(880)	(1)	(187)
Lapse of statute of limitations	(53)	(11)	0
End of year	$ 2,485	$ 3,716	$ 3,210