Accumulated Other Comprehensive Income (Loss) - Summary of Accumulated Other Comprehensive (Loss) (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance				$ 458,907	$ 363,024
Pre-tax Activity		$ 975	$ 728	2,919	2,186
Tax Effect		(241)	(281)	(720)	(843)
Ending Balance		468,563	383,116	468,563	383,116
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		8	5	14	(11)
Pre-tax Activity		(2)	11	(10)	37
Tax Effect		1	(4)	3	(14)
Ending Balance		7	12	7	12
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(92,737)	(92,001)	(94,202)	(92,897)
Ending Balance		(92,003)	(91,554)	(92,003)	(91,554)
Net Pension Activity [Member] | Actuarial Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(77,212)	(71,402)	(78,618)	(72,393)
Pre-tax Activity		934	807	2,800	2,421
Tax Effect		(231)	(311)	(691)	(934)
Ending Balance		(76,509)	(70,906)	(76,509)	(70,906)
Net Pension Activity [Member] | Prior Service Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(34)	(52)	(43)	(61)
Pre-tax Activity		6	7	18	21
Tax Effect		(2)	(3)	(5)	(8)
Ending Balance		(30)	(48)	(30)	(48)
Net Postretirement Benefits Activity [Member] | October 2017 Divestitures [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	[1]	6,220		6,220
Ending Balance	[1]	6,220		6,220
Net Postretirement Benefits Activity [Member] | Actuarial Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		(22,767)	(23,315)	(23,519)	(24,111)
Pre-tax Activity		499	648	1,497	1,944
Tax Effect		(123)	(250)	(369)	(750)
Ending Balance		(22,391)	(22,917)	(22,391)	(22,917)
Net Postretirement Benefits Activity [Member] | Prior Service Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		1,048	2,763	1,744	3,679
Pre-tax Activity		(462)	(745)	(1,386)	(2,237)
Tax Effect		114	287	342	863
Ending Balance		$ 700	$ 2,305	$ 700	$ 2,305

[1] Recognized loss due to the divestiture of the Deep South and Somerset Exchange Business and the Florence and Laurel Distribution Business during the fourth quarter of 2017.