Restructuring and Cost Reduction Activities - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017	Dec. 30, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and related activities cash implementation costs recovery time frame			5 years
Restructuring and related costs since inception of program	$ 1,402		$ 1,402
Restructuring charges	5	$ 96	25	$ 238
Exit cost reserves	76		76		$ 160
COGS
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(4)	24	9	37
Selling General and Administrative Expenses
Restructuring Cost and Reserve [Line Items]
Restructuring charges	9	75	16	200
Other (income) expense, net
Restructuring Cost and Reserve [Line Items]
Restructuring charges		(3)		1
Employee related costs
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	539		539
Restructuring charges	1	28	5	135
Exit cost reserves	59		59		97
Asset related costs
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	259		259
Restructuring charges	(14)	20	(10)	30
Exit cost reserves	0		0		0
Asset impairment
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	155		155
Restructuring charges	0	0	0	0
Exit cost reserves	0		0		0
Other costs
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	586		586
Restructuring charges	18	51	30	72
Exit cost reserves	17		17		$ 63
Project K [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	1,402		1,402
Project K [Member] | Revenue
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	6		6
Project K [Member] | COGS
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	803		803
Project K [Member] | Selling General and Administrative Expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	730		730
Project K [Member] | Other (income) expense, net
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	(137)		(137)
Project K [Member] | Minimum [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost	1,500		1,500
Project K [Member] | Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost	1,600		1,600
Estimated after-tax cash costs for program, including incremental capital investments			$ 1,100
Project K [Member] | U.S. Snacks
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost allocation			34.00%
Project K [Member] | U.S. Morning Foods
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost allocation			17.00%
Project K [Member] | U.S. Specialty Channels
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost allocation			1.00%
Project K [Member] | North America Other
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost allocation			13.00%
Project K [Member] | Europe
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost allocation			22.00%
Project K [Member] | Latin America
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost allocation			2.00%
Project K [Member] | Asia Pacific
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost allocation			6.00%
Project K [Member] | Employee related costs | Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost	500		$ 500
Project K [Member] | Asset related costs | Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost	500		500
Project K [Member] | Other costs | Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost	600		600
Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	20		20
Restructuring charges	$ 1	$ 5	$ 2	$ 11
Corporate | Project K [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost allocation			5.00%