Employee related obligations - Narrative (Details) - USD ($) $ in Millions	Dec. 28, 2025	Dec. 29, 2024
Compensation Related Costs [Abstract]
Prepaid employee related obligations	$ 7,300	$ 6,000

Amount of asset, recognized in statement of financial position, for overfunded defined benefit pension and other postretirement plans.

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Name:	us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant