Revenue Recognition - Contract Balances (Details) - USD ($)		3 Months Ended		6 Months Ended
	Jan. 01, 2018	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018	Dec. 30, 2018
Revenue, Major Customer [Line Items]
Cumulative effect of adoption of Topic 606	$ (24,359,000)
Revenue recognized related to deferred revenue and customer loyalty program		$ 8,400,000	$ 3,200,000	$ 15,800,000	$ 7,300,000
Contract liabilities		39,222,000		39,222,000		$ 41,291,000
Change				(2,069,000)
Contract assets		6,200,000		6,200,000		6,600,000
Amortization expense related to contract assets		800,000		1,600,000
Deferred revenue.
Revenue, Major Customer [Line Items]
Contract liabilities		20,057,000		20,057,000		23,272,000
Change				(3,215,000)
Customer loyalty program
Revenue, Major Customer [Line Items]
Contract liabilities		$ 19,165,000		19,165,000		$ 18,019,000
Change				$ 1,146,000
As reported
Revenue, Major Customer [Line Items]
Cumulative effect of adoption of Topic 606	$ (21,528,000)