Restructuring and Cost Reduction Activities - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 01, 2017	Jul. 02, 2016	Jul. 01, 2017	Jul. 02, 2016	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring plan, number of years			5 years
Restructuring and related costs since inception of program	$ 1,392		$ 1,392
Restructuring charges	96	$ 72	238	$ 124
Exit cost reserves	221		221		$ 131
COGS
Restructuring Cost and Reserve [Line Items]
Restructuring charges	20	36	35	54
Selling General and Administrative Expenses
Restructuring Cost and Reserve [Line Items]
Restructuring charges	76	36	203	70
Employee related costs
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	504		504
Restructuring charges	25	6	136	20
Exit cost reserves	187		187		102
Asset related costs
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	222		222
Restructuring charges	20	17	30	27
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	16	0	16
Exit cost reserves	0		0		0
Other costs
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	511		511
Restructuring charges	51	33	72	61
Exit cost reserves	34		34		$ 29
Project K
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	1,354		1,354
Project K | Revenue
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	6		6
Project K | COGS
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	725		725
Project K | Selling General and Administrative Expenses
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	623		623
Project K | Minimum
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost	1,500		1,500
Project K | Maximum
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 | U.S. Morning Foods
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost allocation			13.00%
Project K | U.S. Snacks
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost allocation			35.00%
Project K | U.S. Specialty
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost allocation			1.00%
Project K | North America Other
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost allocation			11.00%
Project K | Europe
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost allocation			21.00%
Project K | Latin America
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost allocation			1.00%
Project K | Asia Pacific
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost allocation			6.00%
Project K | Employee related costs | Maximum
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost	500		$ 500
Project K | Asset related costs | Maximum
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost	500		500
Project K | Other costs | Maximum
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs, expected cost	600		600
Zero Based Budgeting
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	38		38
Restructuring Charges	1			17
Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and related costs since inception of program	171		171
Restructuring charges	$ 5	$ 7	$ 11	$ 9
Corporate | Project K
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost allocation			12.00%