Leases - Schedule of supplemental cash flow information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2020	Mar. 30, 2019
Supplemental Cash Flow Information
Operating cash flows from operating leases	$ 3,520	$ 2,280
Financing cash flows from finance leases	267	163
Right-of-use assets obtained in exchange for lease obligations
Operating leases	$ 4,990	$ 1,062