Reportable Segments Supplemental Product Information (Details) - USD ($) $ in Millions	3 Months Ended
Apr. 02, 2022	Apr. 03, 2021
Segment Reporting Information [Line Items]
Net sales	$ 3,672	$ 3,584
Snacks
Segment Reporting Information [Line Items]
Net sales	1,775	1,647
Cereal
Segment Reporting Information [Line Items]
Net sales	1,281	1,374
Frozen
Segment Reporting Information [Line Items]
Net sales	291	297
Noodles and other
Segment Reporting Information [Line Items]
Net sales	$ 325	$ 266

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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+ Details