Description of business, basis of presentation, and summary of significant accounting policies - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 30, 2018
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 1,093,098	$ 558,864
Accumulated depreciation	(277,291)	(219,256)
Net property, plant and equipment	815,807	339,608
Land
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	105,805	39,036
Buildings and improvements
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	416,537	204,753
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	474,418	274,748
Furniture, fixtures, and computer software
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	82,651	35,679
Construction in progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 13,687	$ 4,648