Leases - Cash paid for amounts included in the measurement of lease liabilities (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 29, 2019	Jun. 29, 2019
Leases [Abstract]
Financing cash flows from finance leases	$ 908	$ 1,805
Operating cash flows from finance leases	395	800
Operating cash flows from operating leases	$ 89,515	$ 162,980