Accumulated Other Comprehensive Loss - Summary of Impact of Accumulated Other Comprehensive Income (Loss) on Income Statement (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014
Defined Benefit Plan Disclosure [Line Items]
Reclassification to income, Pre-tax Activity	$ 681	$ 644	$ 2,045	$ 1,876
Reclassification to income, Tax Effect	260	249	787	726
Reclassification to income, Net of Tax	421	395	1,258	1,150
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Reclassification to income, Pre-tax Activity	804	459	2,413	1,321
Reclassification to income, Tax Effect	307	177	928	510
Reclassification to income, Net of Tax	497	282	1,485	811
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Reclassification to income, Pre-tax Activity	(123)	185	(368)	555
Reclassification to income, Tax Effect	(47)	72	(141)	216
Reclassification to income, Net of Tax	(76)	113	(227)	339
Cost of Sales [Member]
Defined Benefit Plan Disclosure [Line Items]
Reclassification to income, Pre-tax Activity	71	107	213	310
Cost of Sales [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Reclassification to income, Pre-tax Activity	88	83	265	238
Cost of Sales [Member] | Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Reclassification to income, Pre-tax Activity	(17)	24	(52)	72
S,D&A Expenses [Member]
Defined Benefit Plan Disclosure [Line Items]
Reclassification to income, Pre-tax Activity	610	537	1,832	1,566
S,D&A Expenses [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Reclassification to income, Pre-tax Activity	716	376	2,148	1,083
S,D&A Expenses [Member] | Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Reclassification to income, Pre-tax Activity	$ (106)	$ 161	$ (316)	$ 483