RESTRUCTURING - Narrative (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 28, 2024 USD ($)	Sep. 28, 2024 USD ($)
Restructuring Cost and Reserve [Line Items]
Program costs to date	$ 121	$ 121
Restructuring charges	$ 12	121
Minimum [Member]
Restructuring Cost and Reserve [Line Items]
Cash implementation costs	1
Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Cash implementation costs	5
North America
Restructuring Cost and Reserve [Line Items]
Program costs to date	$ 47	47
Restructuring charges	7	47
Employee Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Program costs to date	41	41
Restructuring charges	4	41
Asset related costs [Member]
Restructuring Cost and Reserve [Line Items]
Program costs to date	9	9
Restructuring charges	1	9
Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges		11
North America Frozen Supply Chain Network Reconfiguration
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	50	50
North America Frozen Supply Chain Network Reconfiguration | COGS
Restructuring Cost and Reserve [Line Items]
Restructuring charges	7	47
North America Frozen Supply Chain Network Reconfiguration | Employee Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	10	10
North America Frozen Supply Chain Network Reconfiguration | Asset related costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	30	30
North America Frozen Supply Chain Network Reconfiguration | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	10	10
European Cereal Supply Chain Network Reconfiguration
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	120	120
Restructuring charges	5	74
European Cereal Supply Chain Network Reconfiguration | Employee Related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	50	50
European Cereal Supply Chain Network Reconfiguration | Asset related costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	40	40
European Cereal Supply Chain Network Reconfiguration | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	$ 30	$ 30