Restructuring and Cost Reduction Activities - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 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	$ 1,436		$ 1,436
Restructuring charges	34	$ 1	59	$ 239
Exit cost reserves	83		83		$ 160
COGS
Restructuring Cost and Reserve [Line Items]
Restructuring charges	49	49	58	85
Selling General and Administrative Expenses
Restructuring Cost and Reserve [Line Items]
Restructuring charges	15	86	31	287
Other (income) expense, net
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(30)	(134)	(30)	(133)
Employee related costs
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	556		556
Restructuring charges	17	31	22	166
Exit cost reserves	67		67		97
Asset related costs
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	269		269
Restructuring charges	10	38	0	68
Exit cost reserves	3		3		0
Asset impairment
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	169		169
Restructuring charges	14	0	14	0
Exit cost reserves	0		0		0
Other costs
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	609		609
Restructuring charges	23	66	53	138
Exit cost reserves	13		13		$ 63
Project K [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	1,436		1,436
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	852		852
Project K [Member] | Selling General and Administrative Expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	745		745
Project K [Member] | Other (income) expense, net
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	(167)		(167)
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			32.00%
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			15.00%
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			3.00%
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	21		21
Restructuring charges	$ 1	$ (139)	$ 3	$ (128)
Corporate | Project K [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost allocation			4.00%