Reportable Segments (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 29, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 29, 2018 USD ($)	Sep. 30, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments			10
Number of remaining reportable segments based on geographical locations			3
Net sales	$ 3,469	$ 3,246	$ 10,230	$ 9,669
Operating profit	396	333	1,380	998
Operating Segments
Segment Reporting Information [Line Items]
Operating profit	467	404	1,519	1,240
Operating Segments | U.S. Snacks
Segment Reporting Information [Line Items]
Net sales	737	764	2,244	2,374
Operating profit	119	13	332	6
Operating Segments | U.S. Morning Foods
Segment Reporting Information [Line Items]
Net sales	683	692	2,017	2,064
Operating profit	112	132	400	459
Operating Segments | U.S. Specialty Channels
Segment Reporting Information [Line Items]
Net sales	285	288	960	956
Operating profit	62	76	202	242
Operating Segments | North America Other
Segment Reporting Information [Line Items]
Net sales	483	419	1,424	1,201
Operating profit	37	65	180	173
Operating Segments | Europe
Segment Reporting Information [Line Items]
Net sales	596	599	1,804	1,679
Operating profit	74	71	245	214
Operating Segments | Latin America
Segment Reporting Information [Line Items]
Net sales	239	235	710	687
Operating profit	28	23	70	82
Operating Segments | Asia Pacific
Segment Reporting Information [Line Items]
Net sales	446	249	1,071	708
Operating profit	35	24	90	64
Corporate
Segment Reporting Information [Line Items]
Operating profit	$ (71)	$ (71)	$ (139)	$ (242)