Equity method investments - Unaudited financial information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Apr. 01, 2023
Schedule of Equity Method Investments [Line Items]
Assets	$ 997,072	$ 948,465
Sales/ Total revenues and other income	85,393		$ 70,843
Subsequent Event [Member]
Schedule of Equity Method Investments [Line Items]
Assets				$ 90,943
Liabilities				$ 41,590
The Kraft Heinz Company [Member]
Schedule of Equity Method Investments [Line Items]
Assets		90,513
Liabilities		41,643
Sales/ Total revenues and other income	6,489		6,045
Net earnings attributable to common shareholders	$ 836		$ 776
Occidental Petroleum Corporation [Member]
Schedule of Equity Method Investments [Line Items]
Assets		72,609
Liabilities		42,524
Sales/ Total revenues and other income		8,326
Net earnings attributable to common shareholders		$ 1,727