Leases - Supplemental balance sheet information (Details) - USD ($) $ in Thousands	Sep. 26, 2020	Dec. 31, 2019
Operating Leases
Right of use operating lease assets	$ 303,050	$ 323,003
Finance Leases
Property, plant and equipment, gross	48,347	35,271
Accumulated depreciation	(10,203)	(5,664)
Property, plant and equipment, net	38,144	29,607
Total lease assets	341,194	352,610
Operating Leases
Other current	97,778	101,945
Non-current	214,654	228,155
Total operating liabilities	312,432	330,100
Finance Leases
Short-term debt	7,033	4,835
Long-term debt	31,747	25,214
Total finance liabilities	38,780	30,049
Total lease liabilities	$ 351,212	$ 360,149
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentNet