Restructuring, acquisition and integration-related costs - Restructuring and Related Costs by Type of Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring costs			$ 73,749	$ 37,758
Estimated remaining restructuring costs	$ 70		70
Cost of sales
Restructuring Cost and Reserve [Line Items]
Restructuring costs	49,500	$ 4,379	60,672	35,913
Acquisition integration-related costs	543	1,488	1,153	2,556
Restructuring, acquisition transaction and integration-related costs	50,043	5,867	61,825	38,469
Selling, general and administrative expenses
Restructuring Cost and Reserve [Line Items]
Restructuring costs	12,540	443	13,077	1,845
Acquisition transaction-related costs	6	637	(210)	917
Acquisition integration-related costs	990	1,988	1,565	3,407
Restructuring, acquisition transaction and integration-related costs	$ 13,536	$ 3,068	$ 14,432	$ 6,169