Equity method investments - Unaudited financial information (Detail) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Jul. 01, 2023	Dec. 31, 2022
Schedule Of Equity Method Investments [Line Items]
Assets	$ 1,041,573			$ 1,041,573				$ 948,465
Liabilities	489,812			489,812				466,784
Sales/ Total revenues and other income	92,503		$ 76,201	177,896		$ 147,044
The Kraft Heinz Company [Member]
Schedule Of Equity Method Investments [Line Items]
Assets								90,513
Liabilities								41,643
Sales/ Total revenues and other income	6,721		6,554	13,210		12,599
Net earnings attributable to common shareholders	$ 1,000		$ 265	$ 1,836		$ 1,041
The Kraft Heinz Company [Member] | Subsequent Event [Member]
Schedule Of Equity Method Investments [Line Items]
Assets							$ 90,956
Liabilities							$ 40,942
Occidental Petroleum Corporation [Member]
Schedule Of Equity Method Investments [Line Items]
Assets		$ 71,600			$ 71,600			72,609
Liabilities		42,041			42,041			$ 42,524
Sales/ Total revenues and other income		7,258			15,584
Net earnings attributable to common shareholders		$ 983			$ 2,710