Accumulated Other Comprehensive Earnings (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Sep. 29, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 28, 2013 Foreign Currency Translation	Jun. 29, 2013 Foreign Currency Translation	Mar. 30, 2013 Foreign Currency Translation	Sep. 29, 2012 Foreign Currency Translation	Jun. 30, 2012 Foreign Currency Translation	Mar. 31, 2012 Foreign Currency Translation	Sep. 28, 2013 Investments	Jun. 29, 2013 Investments	Mar. 30, 2013 Investments	Sep. 29, 2012 Investments	Jun. 30, 2012 Investments	Mar. 31, 2012 Investments	Sep. 28, 2013 Foreign Currency Derivatives	Jun. 29, 2013 Foreign Currency Derivatives	Mar. 30, 2013 Foreign Currency Derivatives	Sep. 29, 2012 Foreign Currency Derivatives	Jun. 30, 2012 Foreign Currency Derivatives	Mar. 31, 2012 Foreign Currency Derivatives	Sep. 28, 2013 Commodity Derivatives	Jun. 29, 2013 Commodity Derivatives	Mar. 30, 2013 Commodity Derivatives	Sep. 29, 2012 Commodity Derivatives	Jun. 30, 2012 Commodity Derivatives	Mar. 31, 2012 Commodity Derivatives	Sep. 29, 2012 Postretirement and Pension Benefits	Sep. 28, 2013 Postretirement and Pension Benefits	Jun. 29, 2013 Postretirement and Pension Benefits	Mar. 30, 2013 Postretirement and Pension Benefits	Dec. 31, 2012 Postretirement and Pension Benefits	Mar. 31, 2012 Postretirement and Pension Benefits	Dec. 31, 2011 Postretirement and Pension Benefits
Accumulated other comprehensive earnings (loss)
Balance at the beginning of the period	$ (17,182)	$ (16,164)	$ (16,447)	$ (19,910)	$ (18,281)	$ (19,953)	$ (13,496)	$ (12,265)	$ (13,406)	$ (14,319)	$ (12,880)	$ (14,686)	$ 793	$ 417	$ 908	$ (375)	$ (703)	$ (351)	$ (484)	$ (158)		$ 44	$ 195	$ 129	$ (157)	$ (320)	$ (111)	$ (87)	$ 280	$ 128	$ (5,173)	$ (3,838)	$ (3,838)	$ (3,838)	$ (3,838)	$ (5,173)	$ (5,173)
Other comprehensive earnings (loss) before reclassifications	1,024	(1,436)	(578)	2,245	(1,695)	1,811	(144)	(1,223)	1,122	1,303	(1,510)	1,851	400	589	(770)	869	514	(546)	626	(585)	(282)	94	(124)	252	142	(217)	(648)	(21)	(575)	254
Reclassifications from accumulated other comprehensive loss	315	546	355	41	(115)	(167)													162	73	35	(164)	(115)	(149)	153	473	320	205		(18)
Net other comprehensive earnings (loss) before tax	1,339	(890)	(223)	2,286	(1,810)	1,644	(144)	(1,223)	1,122	1,303	(1,510)	1,851	400	589	(770)	869	514	(546)	788	(512)	(247)	(70)	(239)	103	295	256	(328)	184	(575)	236	(5,173)
Income tax benefit (expense)	(560)	(128)	506	(378)	181	28	(23)	(8)	19	(23)	71	(45)	(145)	(213)	279	(315)	(186)	194	(285)	186	89	25	88	(37)	(107)	(93)	119	(65)	208	(84)
Balance at the end of the period	$ (16,403)	$ (17,182)	$ (16,164)	$ (18,002)	$ (19,910)	$ (18,281)	$ (13,663)	$ (13,496)	$ (12,265)	$ (13,039)	$ (14,319)	$ (12,880)	$ 1,048	$ 793	$ 417	$ 179	$ (375)	$ (703)	$ 19	$ (484)	$ (158)	$ (1)	$ 44	$ 195	$ 31	$ (157)	$ (320)	$ 32	$ (87)	$ 280	$ (5,173)	$ (3,838)	$ (3,838)	$ (3,838)	$ (3,838)	$ (5,173)	$ (5,173)