Restructuring and Cost Reduction Activities - Schedule of Restructuring and Cost Reduction Activities (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 5	$ 96	$ 25	$ 238
Program costs to date	1,402		1,402
Employee related costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1	28	5	135
Program costs to date	539		539
Pension curtailment (gain) loss, net
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	(3)	0	1
Program costs to date	(137)		(137)
Asset impairment
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	0	0	0
Program costs to date	155		155
Asset related costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(14)	20	(10)	30
Program costs to date	259		259
Other costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges	18	51	30	72
Program costs to date	586		586
Operating Segments | U.S. Snacks
Restructuring Cost and Reserve [Line Items]
Restructuring charges	3	79	9	199
Program costs to date	512		512
Operating Segments | U.S. Morning Foods
Restructuring Cost and Reserve [Line Items]
Restructuring charges	10	1	12	2
Program costs to date	263		263
Operating Segments | U.S. Specialty Channels
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	1	0	1
Program costs to date	21		21
Operating Segments | North America Other
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(1)	2	1	9
Program costs to date	141		141
Operating Segments | Europe
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(13)	2	(6)	8
Program costs to date	324		324
Operating Segments | Latin America
Restructuring Cost and Reserve [Line Items]
Restructuring charges	2	3	4	4
Program costs to date	31		31
Operating Segments | Asia Pacific
Restructuring Cost and Reserve [Line Items]
Restructuring charges	3	3	3	4
Program costs to date	90		90
Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1	$ 5	2	$ 11
Program costs to date	$ 20		$ 20