Leases Supplemental Balance Sheet Information Related To Leases (Details) - USD ($) $ in Thousands	Sep. 27, 2020	Dec. 31, 2019
Leases [Abstract]
Total operating lease right-of-use assets	$ 57,380	$ 62,251
Accrued liabilities	14,657	13,900
Long-term operating lease liabilities	49,209	55,652
Total operating lease liabilities	63,866	69,552
Other long-lived assets, at cost	759	823
Accumulated depreciation	(449)	(391)
Other long-lived assets, net	$ 310	$ 432
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccruedLiabilitiesCurrent
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssetsNoncurrent