Income Taxes (Details) $ in Thousands, kr in Millions	3 Months Ended		6 Months Ended
	Jul. 03, 2021 USD ($)	Jul. 04, 2020 USD ($)	Jul. 03, 2021 USD ($)	Jul. 03, 2021 NOK (kr)	Jul. 04, 2020 USD ($)
Income Taxes
Provision (benefit) for income taxes	$ 1,165	$ (4,229)	$ 3,157		$ (8,443)
Effective income tax rate (as a percent)	(6.70%)	10.50%	(7.80%)	(7.80%)	11.10%
Income tax expense (benefit), continuing operations	$ 9,600		$ 9,600
Gross unrecognized tax benefits	3,400		3,400
Gross unrecognized tax benefits which would affect the effective tax rate if recognized	$ 2,700		2,700
Norwegian | 2013 | Under appeal
Income Taxes
Additional income tax expense			$ 16,400	kr 141.3