Accounting Policies - Narrative (Details) - USD ($) $ in Millions	Mar. 28, 2020	Dec. 28, 2019
Accounting Policies [Abstract]
Obligations placed in accounts payable tracking system	$ 843	$ 812
Obligations sold by participating suppliers	$ 639	$ 605

Amount of payables financed by suppliers that had been placed on the accounts payable tracking system which facilitates participating suppliers' ability to finance payment obligations from the company with designated third party financial institutions.

No definition available.

Name:	k_PayablesPlacedOnTrackingSystem
Namespace Prefix:	k_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant