Leases - Supplemental balance sheet information (Details) - USD ($) $ in Thousands	Jun. 27, 2020	Dec. 31, 2019
Operating Leases
Right of use operating lease assets	$ 318,047	$ 323,003
Finance Leases
Property, plant and equipment, gross	40,346	35,271
Accumulated depreciation	(8,358)	(5,664)
Property, plant and equipment, net	31,988	29,607
Total lease assets	350,035	352,610
Operating Leases
Other current	118,296	101,945
Non-current	226,555	228,155
Total operating liabilities	344,851	330,100
Finance Leases
Short-term debt	5,714	4,835
Long-term debt	27,064	25,214
Total finance liabilities	32,778	30,049
Total lease liabilities	$ 377,629	$ 360,149
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentNet