Income Taxes (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 29, 2019	Jun. 30, 2018	Jun. 29, 2019	Jun. 30, 2018	Dec. 29, 2018
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Income tax expense	$ 180,000	$ 1,343,000	$ 414,000	$ 1,940,000
Unrecognized tax benefits that could significantly change during the next twelve months	1,500,000		1,500,000
Unrecognized tax benefits, associated interest and penalties that could significantly change within the next twelve months	100,000		100,000
Total potential decrease in UTB	1,600,000		1,600,000
Uncertain tax position exposure netted against deferred tax assets	24,800,000		24,800,000
Other Long-term Liabilities
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Uncertain tax positions	$ 25,900,000		25,900,000		$ 26,300,000
Bermuda
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Income tax expense			$ 0
Statutory tax rate			0.00%