Basis of presentation - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2020	Sep. 29, 2019	Sep. 27, 2020	Sep. 29, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Intangible asset amortization expense			$ 118,649	$ 112,661
Cost of Goods Sold
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Intangible asset amortization expense	$ 21,200		$ 63,200
Cost of Goods Sold | Restatement Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Intangible asset amortization expense		$ 20,600		62,100
Selling, General and Administrative Expenses | Restatement Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Intangible asset amortization expense		$ (20,600)		$ (62,100)