Income Taxes (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jul. 01, 2017	Jul. 02, 2016	Jul. 01, 2017	Jul. 02, 2016	Dec. 31, 2016
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Income tax provision	$ 47,000	$ 4,539,000	$ 565,000	$ 6,439,000
Statutory income tax rate	35.00%
Unrecognized tax benefits that could significantly change during the next twelve months	$ 1,600,000		1,600,000
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
Tax credit carryforward, amount					$ 105,900,000
U.S. Federal
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Statutory income tax rate			35.00%
Bermuda
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Income tax provision			$ 0
Statutory income tax rate			0.00%
Internal Revenue Service (IRS)
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Operating loss carryforwards					367,000,000
Tax credit carryforward, amount					49,200,000
State and Local Jurisdiction
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Operating loss carryforwards					193,300,000
Tax credit carryforward, amount					56,700,000
Other Long-term Liabilities
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Uncertain tax positions	$ 27,800,000		$ 27,800,000		29,600,000
No Expiration Date
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Tax credit carryforward, amount					$ 55,500,000