Accumulated Other Comprehensive Income - Changes by Component (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Changes in accumulated other comprehensive income [Roll Forward]
Beginning balance			$ 936,437
Total other comprehensive income (loss), net	$ 6,080	$ 1,466	13,417	$ (4,374)
Ending balance	530,037		530,037
Total [Member]
Changes in accumulated other comprehensive income [Roll Forward]
Beginning balance			(66,956)	(54,990)
Other comprehensive income (loss) before reclassifications			14,638	(4,307)
Amounts reclassified from AOCI			(2,059)	896
Total other comprehensive income (loss), net			12,579	(3,411)
Ending balance	(54,377)	(58,401)	(54,377)	(58,401)
Cumulative Translation Adjustment [Member]
Changes in accumulated other comprehensive income [Roll Forward]
Beginning balance			(49,965)	(24,773)
Other comprehensive income (loss) before reclassifications			18,209	(14,638)
Amounts reclassified from AOCI			(3,777)	0
Total other comprehensive income (loss), net			14,432	(14,638)
Ending balance	(35,533)	(39,411)	(35,533)	(39,411)
Unrealized (Loss) Gain on Derivatives [Member]
Changes in accumulated other comprehensive income [Roll Forward]
Beginning balance			(300)	(2,009)
Other comprehensive income (loss) before reclassifications			(1,175)	1,446
Amounts reclassified from AOCI			1,360	(291)
Total other comprehensive income (loss), net			185	1,155
Ending balance	(115)	(854)	(115)	(854)
Pension/OPEB Liability Adjustment [Member]
Changes in accumulated other comprehensive income [Roll Forward]
Beginning balance			(23,046)	(28,429)
Other comprehensive income (loss) before reclassifications			(1,309)	2,258
Amounts reclassified from AOCI			737	1,187
Total other comprehensive income (loss), net			(572)	3,445
Ending balance	(23,618)	(24,984)	(23,618)	(24,984)
Unrealized Gain (Loss) on Equity Securities [Member]
Changes in accumulated other comprehensive income [Roll Forward]
Beginning balance			380	221
Other comprehensive income (loss) before reclassifications			(1)	77
Amounts reclassified from AOCI			(379)	0
Total other comprehensive income (loss), net			(380)	77
Ending balance	0	298	0	298
Attributable to Unconsolidated Affiliates [Member]
Changes in accumulated other comprehensive income [Roll Forward]
Beginning balance			5,975	0
Other comprehensive income (loss) before reclassifications			(1,086)	6,550
Amounts reclassified from AOCI			0	0
Total other comprehensive income (loss), net			(1,086)	6,550
Ending balance	$ 4,889	$ 6,550	$ 4,889	$ 6,550