Leases - Supplemental cash flow information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2020	Mar. 30, 2019
Cash paid for amounts included in measurement of lease liabilities:
Operating cash flows from operating leases	$ 31,343	$ 31,557
Operating cash flows from finance leases	110	31
Financing cash flows from finance leases	1,288	371
Right-of-use assets obtained in exchange for lease obligations:
Operating Leases	39,911	22,243
Finance Leases	1,531	0
Amortization of right of use operating lease assets	$ 30,189	$ 28,641