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DESCRIPTION OF THE COMPANY AND BASIS OF PRESENTATION - Allocation of Expenses from Kellanova (Details) $ in Millions	3 Months Ended					6 Months Ended	9 Months Ended	12 Months Ended
	Dec. 28, 2024 USD ($)	Sep. 28, 2024 USD ($)	Jun. 29, 2024 USD ($)	Mar. 30, 2024 USD ($)	Dec. 30, 2023 USD ($)	Jun. 29, 2024 USD ($)	Sep. 28, 2024 USD ($)	Dec. 28, 2024 USD ($) segment	Dec. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Related Party Transaction [Line Items]
Cost of goods sold	$ 442	$ 491	$ 469	$ 502	$ 462	$ 971	$ 1,462	$ 1,904	$ 2,006	$ 2,064
Selling, general and administrative expense	163	162	149	157	165			631	662	556
Other income (expense), net	$ 2	$ 2	$ (4)	$ (6)	$ (10)			$ (6)	(63)	101
Number of reportable segments \| segment								1
Kellanova
Related Party Transaction [Line Items]
Cost of goods sold									128	172
Selling, general and administrative expense									233	308
Other income (expense), net									(43)	106
Total									$ 318	$ 586