Accumulated Other Comprehensive Earnings (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended								3 Months Ended		9 Months Ended				3 Months Ended		9 Months Ended					3 Months Ended	9 Months Ended
	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014 Reclassified from Accumulated OCI into Earnings	Sep. 28, 2013 Reclassified from Accumulated OCI into Earnings	Sep. 27, 2014 Reclassified from Accumulated OCI into Earnings	Sep. 28, 2013 Reclassified from Accumulated OCI into Earnings	Sep. 27, 2014 Foreign Currency Translation Adjustment	Sep. 28, 2013 Foreign Currency Translation Adjustment	Sep. 27, 2014 Investments	Sep. 28, 2013 Investments	Sep. 27, 2014 Foreign Currency Derivatives	Sep. 28, 2013 Foreign Currency Derivatives	Sep. 27, 2014 Foreign Currency Derivatives Reclassified from Accumulated OCI into Earnings	Sep. 28, 2013 Foreign Currency Derivatives Reclassified from Accumulated OCI into Earnings	Sep. 27, 2014 Foreign Currency Derivatives Reclassified from Accumulated OCI into Earnings	Sep. 28, 2013 Foreign Currency Derivatives Reclassified from Accumulated OCI into Earnings	Sep. 27, 2014 Commodity Derivatives	Sep. 28, 2013 Commodity Derivatives	Sep. 27, 2014 Commodity Derivatives Reclassified from Accumulated OCI into Earnings	Sep. 28, 2013 Commodity Derivatives Reclassified from Accumulated OCI into Earnings	Sep. 27, 2014 Commodity Derivatives Reclassified from Accumulated OCI into Earnings	Sep. 28, 2013 Commodity Derivatives Reclassified from Accumulated OCI into Earnings	Sep. 27, 2014 Postretirement and Pension Benefits	Sep. 28, 2013 Postretirement and Pension Benefits	Dec. 31, 2012 Postretirement and Pension Benefits	Sep. 27, 2014 Postretirement and Pension Benefits Reclassified from Accumulated OCI into Earnings	Sep. 27, 2014 Postretirement and Pension Benefits Reclassified from Accumulated OCI into Earnings
Accumulated other comprehensive earnings (loss), net of tax
Balance at the beginning of the period			$ (4,638)	$ (16,447)					$ (13,527)	$ (13,406)	$ 54	$ 908	$ (436)						$ (96)	$ (111)					$ 9,367	$ (3,838)	$ (3,838)
Other comprehensive earnings (loss) before reclassifications			(2,989)	(732)					(1,703)	(257)	(202)	140	(752)	(154)					(332)	(461)
Reclassifications from accumulated other comprehensive loss			(278)	776									398	173					188	603					(864)
Net other comprehensive earnings (loss) net of tax			(3,267)	44					(1,703)	(257)	(202)	140	(354)	19					(144)	142					(864)
Balance at the end of the period	(7,905)	(16,403)	(7,905)	(16,403)					(15,230)	(13,663)	(148)	1,048	(790)	19					(240)	31					8,503	(3,838)	(3,838)
Reclassification from Accumulated Other Comprehensive Income
Other Income	166	3,105	4,865	7,401											173	162	624	270
Product cost of goods sold	123,164	125,833	256,211	264,974																	235	153	294	946				(221)	(663)
Selling, marketing and administrative expenses	31,840	33,166	85,767	87,620																								(230)	(690)
Total before tax	36,925	36,592	66,881	60,990	(43)	315	(435)	1,216
Tax (expense) benefit	(934)	560	(1,368)	182	15	(114)	157	(440)
Net income	$ 26,609	$ 26,043	$ 44,923	$ 43,481	$ (28)	$ 201	$ (278)	$ 776