Leases (Details) $ in Thousands	3 Months Ended
	Mar. 30, 2019 USD ($)
Income and expenses, lessee [Line Items]
Finance lease cost, amortization of right-of-use asset	$ 345
Finance lease cost, interest expense on lease liabilities	34
Total lease cost	5,252
Operating expense [Member]
Income and expenses, lessee [Line Items]
Operating lease cost	1,438
Other lease cost (1)	719
Selling and marketing expense [Member]
Income and expenses, lessee [Line Items]
Operating lease cost	2,167
Other lease cost (1)	346
General and administrative expense [Member]
Income and expenses, lessee [Line Items]
Operating lease cost	201
Other lease cost (1)	$ 2