Accumulated Other Comprehensive Income (Loss) - Summary of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2017	Jul. 03, 2016	Jul. 02, 2017	Jul. 03, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ 363,024	$ 322,432
Pre-tax Activity	$ 738	$ 487	1,458	997
Tax Effect	(284)	(188)	(562)	(385)
Ending Balance	366,091	330,409	366,091	330,409
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(9)	5	(11)	(5)
Pre-tax Activity	22	(8)	26	7
Tax Effect	(8)	2	(10)	(3)
Ending Balance	5	(1)	5	(1)
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(92,455)	(82,094)	(92,897)	(82,407)
Ending Balance	(92,001)	(81,795)	(92,001)	(81,795)
Net Pension Activity [Member] | Actuarial Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(71,897)	(67,788)	(72,393)	(68,243)
Pre-tax Activity	807	740	1,614	1,481
Tax Effect	(312)	(285)	(623)	(571)
Ending Balance	(71,402)	(67,333)	(71,402)	(67,333)
Net Pension Activity [Member] | Prior Service Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(57)	(74)	(61)	(78)
Pre-tax Activity	7	7	14	14
Tax Effect	(2)	(2)	(5)	(5)
Ending Balance	(52)	(69)	(52)	(69)
Net Postretirement Benefits Activity [Member] | Actuarial Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(23,713)	(19,465)	(24,111)	(19,825)
Pre-tax Activity	648	588	1,296	1,175
Tax Effect	(250)	(227)	(500)	(454)
Ending Balance	(23,315)	(19,104)	(23,315)	(19,104)
Net Postretirement Benefits Activity [Member] | Prior Service Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	3,221	5,228	3,679	5,744
Pre-tax Activity	(746)	(840)	(1,492)	(1,680)
Tax Effect	288	324	576	648
Ending Balance	$ 2,763	$ 4,712	$ 2,763	$ 4,712