Accumulated Other Comprehensive Income (Loss) - Summary of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ 363,024	$ 322,432
Pre-tax Activity	$ 728	$ 499	2,186	1,496
Tax Effect	(281)	(192)	(843)	(577)
Ending Balance	383,116	353,941	383,116	353,941
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	5	(1)	(11)	(5)
Pre-tax Activity	11	4	37	11
Tax Effect	(4)	(1)	(14)	(4)
Ending Balance	12	2	12	2
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(92,001)	(81,795)	(92,897)	(82,407)
Ending Balance	(91,554)	(81,488)	(91,554)	(81,488)
Net Pension Activity [Member] | Actuarial Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(71,402)	(67,333)	(72,393)	(68,243)
Pre-tax Activity	807	741	2,421	2,222
Tax Effect	(311)	(286)	(934)	(857)
Ending Balance	(70,906)	(66,878)	(70,906)	(66,878)
Net Pension Activity [Member] | Prior Service Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(52)	(69)	(61)	(78)
Pre-tax Activity	7	7	21	21
Tax Effect	(3)	(3)	(8)	(8)
Ending Balance	(48)	(65)	(48)	(65)
Net Postretirement Benefits Activity [Member] | Actuarial Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(23,315)	(19,104)	(24,111)	(19,825)
Pre-tax Activity	648	587	1,944	1,762
Tax Effect	(250)	(226)	(750)	(680)
Ending Balance	(22,917)	(18,743)	(22,917)	(18,743)
Net Postretirement Benefits Activity [Member] | Prior Service Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	2,763	4,712	3,679	5,744
Pre-tax Activity	(745)	(840)	(2,237)	(2,520)
Tax Effect	287	324	863	972
Ending Balance	$ 2,305	$ 4,196	$ 2,305	$ 4,196