Equity method investments - Financial information (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 26, 2020	Dec. 31, 2019	Dec. 28, 2019	Dec. 31, 2018	Dec. 29, 2018
Schedule of Equity Method Investments [Line Items]
Assets	$ 873,729				$ 817,729				$ 873,729		$ 817,729		$ 707,794
Liabilities	422,393				389,166				422,393		389,166
Sales	$ 64,381	$ 63,024	$ 56,840	$ 61,265	$ 65,368	$ 64,972	$ 63,598	$ 60,678	$ 245,510		$ 254,616		$ 247,837
The Kraft Heinz Company [Member]
Schedule of Equity Method Investments [Line Items]
Assets										$ 99,830		$ 101,450
Liabilities										49,587		49,701
Sales										26,185		24,977		$ 26,268
Net earnings (losses) attributable to Kraft Heinz common shareholders										$ 356		$ 1,935		$ (10,192)