REPORTABLE SEGMENTS - Supplemental Product Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 27, 2025	Sep. 28, 2024	Sep. 27, 2025	Sep. 28, 2024
Segment Reporting Information [Line Items]
Net sales	$ 3,260	$ 3,233	$ 9,546	$ 9,625
Snacks
Segment Reporting Information [Line Items]
Net sales	2,027	2,069	5,932	6,153
Cereal
Segment Reporting Information [Line Items]
Net sales	678	690	1,995	2,066
Frozen
Segment Reporting Information [Line Items]
Net sales	275	276	821	828
Noodles and other
Segment Reporting Information [Line Items]
Net sales	$ 280	$ 198	$ 798	$ 578