Equity method investments - Unaudited financial information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 25, 2021	Dec. 31, 2020	Dec. 26, 2020
Schedule of Equity Method Investments [Line Items]
Assets	$ 920,758		$ 920,758			$ 873,729
Liabilities	439,683		439,683			$ 422,393
Sales	70,583	$ 63,024	204,296	$ 181,129
The Kraft Heinz Company [Member]
Schedule of Equity Method Investments [Line Items]
Assets					$ 94,897		$ 99,830
Liabilities					$ 44,659		$ 49,587
Sales	6,324	6,441	19,333	19,246
Net earnings (loss) attributable to Kraft Heinz common shareholders	$ 733	$ 597	$ 1,269	$ (676)