Reportable Segments Narrative (Details) $ in Millions		3 Months Ended								12 Months Ended
	Jul. 28, 2019 USD ($)	Jan. 02, 2021 USD ($)	Sep. 26, 2020 USD ($)	Jun. 27, 2020 USD ($)	Mar. 28, 2020 USD ($)	Dec. 28, 2019 USD ($)	Sep. 28, 2019 USD ($)	Jun. 29, 2019 USD ($)	Mar. 30, 2019 USD ($)	Jan. 02, 2021 USD ($)	Dec. 28, 2019 USD ($)		Dec. 29, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of Operating Segments										4
Net sales		$ 3,464	$ 3,429	$ 3,465	$ 3,412	$ 3,223	$ 3,372	$ 3,461	$ 3,522	$ 13,770	$ 13,578		$ 13,547
Operating profit										1,761	1,401		1,706
Proceeds from divestiture of businesses										(7)	1,332		0
United States
Segment Reporting Information [Line Items]
Net sales										$ 7,821	$ 7,885		$ 8,176
Walmart Stores Inc [Member] | Customer Concentration Risk [Member] | Sales [Member] | United States
Segment Reporting Information [Line Items]
Concentration Risk, Percentage										19.00%	19.00%		19.00%
North America
Segment Reporting Information [Line Items]
Net sales										$ 8,361	$ 8,390		$ 8,688
Operating profit										$ 1,473	1,215	[1]	1,397	[2]
Cookies, fruit and fruit flavored snacks, pie crusts and ice cream cones businesses
Segment Reporting Information [Line Items]
Proceeds from divestiture of businesses	$ 1,300
Net assets	1,300
Cookies, fruit and fruit flavored snacks, pie crusts and ice cream cones businesses | North America
Segment Reporting Information [Line Items]
Net sales											$ 562		$ 893
Proceeds from divestiture of businesses	1,300
Net assets	$ 1,300

[1] During 2019, North America operating profit includes the recognition of multi-employer pension plan exit liabilities totaling $132 million.

[2] Corporate operating profit in 2020 and 2019 includes the cost of certain global research and development activities that were previously included in the North America reportable segment in 2018 totaling approximately $48 million.