Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 29, 2019	Mar. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Rollward]
Accumulated other comprehensive loss	$ (57,270)	$ (101,221)	$ (58,234)	$ (102,937)
Activity
Other comprehensive income (loss) before reclassifications	825	(276)
Amounts reclassified from accumulated other comprehensive income	530	2,139
Net current period other comprehensive income (loss) before tax	1,355	1,863
Deferred taxes on current period activity	391	147
Net current period other comprehensive income (loss) after tax	964	1,716
Pension and Post Employment Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Rollward]
Accumulated other comprehensive loss	(54,003)	(98,314)	(54,543)	(99,592)
Activity
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income	660	1,626
Net current period other comprehensive income (loss) before tax	660	1,626
Deferred taxes on current period activity	120	348
Net current period other comprehensive income (loss) after tax	540	1,278
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Rollward]
Accumulated other comprehensive loss	(5,095)	(2,995)	(4,592)	(4,108)
Activity
Other comprehensive income (loss) before reclassifications	(503)	1,113
Amounts reclassified from accumulated other comprehensive income	0	0
Net current period other comprehensive income (loss) before tax	(503)	1,113
Deferred taxes on current period activity	0	0
Net current period other comprehensive income (loss) after tax	(503)	1,113
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Rollward]
Accumulated other comprehensive loss	1,828	88	901	763
Activity
Other comprehensive income (loss) before reclassifications	1,328	(1,389)
Amounts reclassified from accumulated other comprehensive income	(130)	513
Net current period other comprehensive income (loss) before tax	1,198	(876)
Deferred taxes on current period activity	271	(201)
Net current period other comprehensive income (loss) after tax	927	(675)
Foreign Currency Forward Contract \| Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Rollward]
Accumulated other comprehensive loss	1,663	326	1,263	959
Activity
Other comprehensive income (loss) before reclassifications	517	(1,198)
Amounts reclassified from accumulated other comprehensive income	2	377
Net current period other comprehensive income (loss) before tax	519	(821)
Deferred taxes on current period activity	119	(188)
Net current period other comprehensive income (loss) after tax	400	(633)
Precious Metal Contracts [Member] \| Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Rollward]
Accumulated other comprehensive loss	(24)	(238)	79	(196)
Activity
Other comprehensive income (loss) before reclassifications	(73)	(191)
Amounts reclassified from accumulated other comprehensive income	(61)	136
Net current period other comprehensive income (loss) before tax	(134)	(55)
Deferred taxes on current period activity	(31)	(13)
Net current period other comprehensive income (loss) after tax	(103)	(42)
Copper Swap [Member] \| Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Rollward]
Accumulated other comprehensive loss	189	0	$ (441)	$ 0
Activity
Other comprehensive income (loss) before reclassifications	884	0
Amounts reclassified from accumulated other comprehensive income	(71)	0
Net current period other comprehensive income (loss) before tax	813	0
Deferred taxes on current period activity	183	0
Net current period other comprehensive income (loss) after tax	$ 630	$ 0

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Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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

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

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

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Amount of tax expense (benefit) allocated to other comprehensive income (loss).

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

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