Accumulated Other Comprehensive (Loss) Income - Summary of Components of Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 28, 2015	Jun. 30, 2016	Jun. 28, 2015
Foreign currency transaction loss
Foreign currency transaction gain (loss)	$ (1,260)	$ 125	$ (1,491)	$ (1,563)
AOCI Attributable to Parent, Net of Tax
Total accumulated other comprehensive (loss) income, beginning of period			(99,005)
Total accumulated other comprehensive (loss) income, end of period	(97,649)		(97,649)
Accumulated other comprehensive (loss) income
AOCI Attributable to Parent, Net of Tax
Total accumulated other comprehensive (loss) income, beginning of period	(98,212)	(104,165)	(99,005)	(104,233)
Gain (Loss) recognized in OCI, Net	(527)	2,145	(785)	2,095
Gain (Loss) reclassified from AOCI to income, Net	1,090	120	2,141	238
Total accumulated other comprehensive (loss) income, end of period	(97,649)	(101,900)	(97,649)	(101,900)
Changes in fair market value of hedges
Changes in AOCI, Gross
Gross, beginning of the period	(295)	(1,157)	(768)	(1,020)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(337)	(82)	(95)	(409)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	229	192	460	382
Gross, ending balance	(403)	(1,047)	(403)	(1,047)
Changes in AOCI, Income tax (benefit)
Income tax (benefit), beginning of period	110	435	289	384
Income tax (benefit), Gain (Loss) recognized in OCI	127	31	36	154
Income tax (benefit), Gain (Loss) reclassified from AOCI to income	(86)	(72)	(174)	(144)
Income tax (benefit), ending of period	151	394	151	394
AOCI Attributable to Parent, Net of Tax
Total accumulated other comprehensive (loss) income, beginning of period	(185)	(722)	(479)	(636)
Gain (Loss) recognized in OCI, Net	(210)	(51)	(59)	(255)
Gain (Loss) reclassified from AOCI to income, Net	143	120	286	238
Total accumulated other comprehensive (loss) income, end of period	(252)	(653)	(252)	(653)
Changes in unrealized pension cost
Changes in AOCI, Gross
Gross, beginning of the period	(160,268)	(167,361)	(161,719)	(169,291)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	0	1,199	0	3,129
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	1,505	0	2,956	0
Gross, ending balance	(158,763)	(166,162)	(158,763)	(166,162)
Changes in AOCI, Income tax (benefit)
Income tax (benefit), beginning of period	63,818	64,451	64,361	65,124
Income tax (benefit), Gain (Loss) recognized in OCI	0	(494)	0	(1,167)
Income tax (benefit), Gain (Loss) reclassified from AOCI to income	(558)	0	(1,101)	0
Income tax (benefit), ending of period	63,260	63,957	63,260	63,957
AOCI Attributable to Parent, Net of Tax
Total accumulated other comprehensive (loss) income, beginning of period	(96,450)	(102,910)	(97,358)	(104,167)
Gain (Loss) recognized in OCI, Net	0	705	0	1,962
Gain (Loss) reclassified from AOCI to income, Net	947	0	1,855	0
Total accumulated other comprehensive (loss) income, end of period	(95,503)	(102,205)	(95,503)	(102,205)
Cumulative translation adjustment
Changes in AOCI, Gross
Gross, beginning of the period	(1,685)	(491)	(1,279)	245
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(310)	1,064	(716)	328
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	0	0	0	0
Gross, ending balance	(1,995)	573	(1,995)	573
Changes in AOCI, Income tax (benefit)
Income tax (benefit), beginning of period	108	(42)	111	325
Income tax (benefit), Gain (Loss) recognized in OCI	(7)	427	(10)	60
Income tax (benefit), Gain (Loss) reclassified from AOCI to income	0	0	0	0
Income tax (benefit), ending of period	101	385	101	385
AOCI Attributable to Parent, Net of Tax
Total accumulated other comprehensive (loss) income, beginning of period	(1,577)	(533)	(1,168)	570
Gain (Loss) recognized in OCI, Net	(317)	1,491	(726)	388
Gain (Loss) reclassified from AOCI to income, Net	0	0	0	0
Total accumulated other comprehensive (loss) income, end of period	$ (1,894)	$ 958	$ (1,894)	$ 958