Equity method investments - Unaudited financial information (Detail) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Sep. 30, 2023	Jun. 30, 2023	Sep. 30, 2024	Jun. 30, 2024	Sep. 30, 2023	Jun. 30, 2023	Sep. 28, 2024	Dec. 31, 2023	Dec. 30, 2023
Schedule Of Equity Method Investments [Line Items]
Assets	$ 1,147,251				$ 1,147,251					$ 1,069,978
Liabilities	515,445				515,445					$ 499,208
Sales/ Total revenues and other income	92,995		$ 93,210		276,517		$ 271,106
The Kraft Heinz Company [Member]
Schedule Of Equity Method Investments [Line Items]
Assets									$ 88,566		$ 90,339
Liabilities									$ 40,097		$ 40,617
Sales/ Total revenues and other income	6,383		6,570		19,270		19,780
Net earnings attributable to common shareholders	$ (290)		262		$ 613		2,098
Occidental Petroleum Corporation [Member]
Schedule Of Equity Method Investments [Line Items]
Assets		$ 76,216	71,287			$ 76,216	71,287
Liabilities		43,957	$ 42,515			43,957	$ 42,515
Sales/ Total revenues and other income		6,879		$ 6,731		20,418		$ 22,315
Net earnings attributable to common shareholders		$ 992		$ 605		$ 2,739		$ 3,315