Accumulated Other Comprehensive Loss - Summary of Impact of Accumulated Other Comprehensive Income (Loss) on Income Statement (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2015	Jun. 29, 2014	Jun. 28, 2015	Jun. 29, 2014
Defined Benefit Plan Disclosure [Line Items]
Reclassification to income, Pre-tax Activity	$ 682	$ 616	$ 1,364	$ 1,232
Reclassification to income, Tax Effect	263	239	527	477
Reclassification to income, Net of Tax	419	377	837	755
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Reclassification to income, Pre-tax Activity	804	431	1,609	862
Reclassification to income, Tax Effect	310	166	621	333
Reclassification to income, Net of Tax	494	265	988	529
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Reclassification to income, Pre-tax Activity	(122)	185	(245)	370
Reclassification to income, Tax Effect	(47)	73	(94)	144
Reclassification to income, Net of Tax	(75)	112	(151)	226
Cost of Sales [Member]
Defined Benefit Plan Disclosure [Line Items]
Reclassification to income, Pre-tax Activity	71	106	143	203
Cost of Sales [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Reclassification to income, Pre-tax Activity	88	82	177	155
Cost of Sales [Member] | Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Reclassification to income, Pre-tax Activity	(17)	24	(34)	48
S,D&A Expenses [Member]
Defined Benefit Plan Disclosure [Line Items]
Reclassification to income, Pre-tax Activity	611	510	1,221	1,029
S,D&A Expenses [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Reclassification to income, Pre-tax Activity	716	349	1,432	707
S,D&A Expenses [Member] | Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Reclassification to income, Pre-tax Activity	$ (105)	$ 161	$ (211)	$ 322