Restructuring and Cost Reduction Activities - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Apr. 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	$ 1,397
Restructuring charges	20	$ 142
Exit cost reserves	94		$ 160
COGS
Restructuring Cost and Reserve [Line Items]
Restructuring charges	13	13
Selling General and Administrative Expenses
Restructuring Cost and Reserve [Line Items]
Restructuring charges	7	125
Other Income (Expense), Net
Restructuring Cost and Reserve [Line Items]
Restructuring charges		4
Employee related costs
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	538
Restructuring charges	4	107
Exit cost reserves	73		97
Asset related costs
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	273
Restructuring charges	4	10
Exit cost reserves	0		0
Asset impairment
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	155
Restructuring charges	0	0
Exit cost reserves	0		0
Other costs
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	568
Restructuring charges	12	21
Exit cost reserves	21		$ 63
Project K [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	1,397
Project K [Member] | Revenue
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	6
Project K [Member] | COGS
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	807
Project K [Member] | Selling General and Administrative Expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	721
Project K [Member] | Other Income (Expense), Net
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	(137)
Project K [Member] | Minimum [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost	1,500
Project K [Member] | Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost	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
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
Project K [Member] | Asset related costs | Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost	500
Project K [Member] | Other costs | Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost	600
Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	19
Restructuring charges	$ 1	$ 6
Corporate | Project K [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost allocation	5.00%