Earnings per share - Reconciliation of Basic Net Earnings per Share to Diluted Net Earnings per Share (Details) - $ / shares	12 Months Ended
	Dec. 29, 2024	Dec. 31, 2023	Jan. 01, 2023	Jan. 02, 2022
Reconciliation of basic net earnings per share to diluted net earnings per share
Basic net earnings per share from continuing operations (in dollars per share)	$ 5.84	$ 5.26	$ 6.23
Basic net earnings per share from discontinued operations (in dollars per share)	0	8.62	0.60
Basic net earnings per share (in dollars per share)	$ 5.84	$ 13.88	$ 6.83
Average shares outstanding — basic (in shares)	2,407,300,000	2,533,500,000	2,625,200,000
Potential shares exercisable under stock option plans (in shares)	77,700,000	94,100,000	140,100,000
Less: shares repurchased under treasury stock method (in shares)	(55,600,000)	(67,200,000)	(101,400,000)
Average shares outstanding - diluted (in shares)	2,429,400,000	2,560,400,000	2,663,900,000
Diluted net earnings per share from continuing operations (in dollars per share)	$ 5.79	$ 5.20	$ 6.14
Diluted net earnings per share from discontinuing operations (in dollars per share)	0	8.52	0.59
Diluted net earnings per share (in dollars per share)	$ 5.79	$ 13.72	$ 6.73
Antidilutive securities excluded from computation of earnings per share (in shares)	54.1	43.0		0.0