Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 30, 2019	Mar. 31, 2018
Income Taxes
Provision (benefit) for income taxes	$ (2,480)	$ (4,371)
Effective income tax rate (as a percent)	(85.00%)	(19.80%)
Gross unrecognized tax benefits	$ 2,100
Gross unrecognized tax benefits which would affect the effective tax rate if recognized	2,100
Unrecognized tax benefits as a result of a lapse in the statute of limitations	300
Reductions for tax positions as a result of a lapse of the applicable statute of limitations	300
2013 \| Norwegian
Income Taxes
Adjustment to the pricing of the intercompany transaction	$ 16,400

An adjustment for pricing of the intercompany transaction as a result of reassessment.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of unrecognized tax benefits.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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