Accumulated Other Comprehensive Items - Reclassification Out of AOCI (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Reclassification Adjustment Out Of Accumulated Other Comprehensive Items [Line Items]
Interest expense	$ (3,547)	$ (1,293)	$ (948)
Cost of revenues	(283,999)	(225,737)	(209,982)
SG&A expenses	(160,515)	(135,753)	(122,814)
Amortization of prior service costs
Reclassification Adjustment Out Of Accumulated Other Comprehensive Items [Line Items]
Total Reclassifications	(95)
Amortization of actuarial losses
Reclassification Adjustment Out Of Accumulated Other Comprehensive Items [Line Items]
Total Reclassifications	(369)
Cash Flow Hedges
Reclassification Adjustment Out Of Accumulated Other Comprehensive Items [Line Items]
Total Reclassifications	(84)
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment Out Of Accumulated Other Comprehensive Items [Line Items]
Total Reclassifications	(548)	(964)	635
Reclassification out of Accumulated Other Comprehensive Income \| Amortization of prior service costs
Reclassification Adjustment Out Of Accumulated Other Comprehensive Items [Line Items]
SG&A expenses	(147)	(147)	(147)
Reclassification out of Accumulated Other Comprehensive Income \| Amortization of actuarial losses
Reclassification Adjustment Out Of Accumulated Other Comprehensive Items [Line Items]
SG&A expenses	(563)	(701)	(576)
Reclassification out of Accumulated Other Comprehensive Income \| Pension and Other Post-retirement Plans
Reclassification Adjustment Out Of Accumulated Other Comprehensive Items [Line Items]
Total (expense) income before income taxes	(710)	(848)	(723)
Income tax benefit (provision)	246	295	249
Total Reclassifications	(464)	(553)	(474)
Reclassification out of Accumulated Other Comprehensive Income \| Cash Flow Hedges
Reclassification Adjustment Out Of Accumulated Other Comprehensive Items [Line Items]
Total (expense) income before income taxes	(127)	(374)	1,259
Income tax benefit (provision)	43	(37)	(150)
Total Reclassifications	(84)	(411)	1,109
Reclassification out of Accumulated Other Comprehensive Income \| Cash Flow Hedges \| Interest Rate Swap
Reclassification Adjustment Out Of Accumulated Other Comprehensive Items [Line Items]
Interest expense	(30)	(174)	(420)
Reclassification out of Accumulated Other Comprehensive Income \| Cash Flow Hedges \| Forward Currency-Exchange Contracts
Reclassification Adjustment Out Of Accumulated Other Comprehensive Items [Line Items]
Revenues	0	(14)	(12)
Cost of revenues	(97)	(186)	0
SG&A expenses	$ 0	$ 0	$ 1,691

The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

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Amount of the cost of borrowed funds accounted for as interest expense.

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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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Amount before tax of reclassification adjustments of other comprehensive income (loss).

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Amount after tax of reclassification adjustments of other comprehensive income (loss).

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Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income (loss).

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.

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