RESTRUCTURING - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 29, 2025	Mar. 30, 2024
Restructuring Cost and Reserve [Line Items]
Program costs to date	$ 149
Restructuring charges	$ 6	$ 101
Minimum [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Activities, Description	1
Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Activities, Description	5
North America
Restructuring Cost and Reserve [Line Items]
Program costs to date	$ 65
Restructuring charges	0	31
Employee Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Program costs to date	48
Restructuring charges	3	37
Asset related costs [Member]
Restructuring Cost and Reserve [Line Items]
Program costs to date	23
Restructuring charges	0	4
Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	3
North America Frozen Supply Chain Network Reconfiguration
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	70
North America Frozen Supply Chain Network Reconfiguration | COGS
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1	31
North America Frozen Supply Chain Network Reconfiguration | Employee Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	10
North America Frozen Supply Chain Network Reconfiguration | Asset related costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	50
North America Frozen Supply Chain Network Reconfiguration | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	10
European Cereal Supply Chain Network Reconfiguration
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	120
Restructuring charges	6	$ 70
European Cereal Supply Chain Network Reconfiguration | Employee Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	50
European Cereal Supply Chain Network Reconfiguration | Asset related costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	40
European Cereal Supply Chain Network Reconfiguration | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	$ 30