Accumulated Other Comprehensive Loss - Summary of Accumulated Other Comprehensive Loss (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 29, 2014	Jun. 30, 2013	Jun. 29, 2014	Jun. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning, balance	$ (57,798)	$ (93,818)	$ (58,176)	$ (94,526)
Pre-tax Activity	616	1,164	1,232	2,329
Tax Effect	(239)	(456)	(477)	(913)
Ending, balance	(57,421)	(93,110)	(57,421)	(93,110)
Net Pension Activity [Member] | Actuarial Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning, balance	(42,769)	(75,897)	(43,028)	(76,407)
Pre-tax Activity	422	838	844	1,676
Tax Effect	(163)	(329)	(326)	(657)
Ending, balance	(42,510)	(75,388)	(42,510)	(75,388)
Net Pension Activity [Member] | Prior Service Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning, balance	(116)	(31)	(121)	(33)
Pre-tax Activity	9	4	18	8
Tax Effect	(3)	(1)	(7)	(3)
Ending, balance	(110)	(28)	(110)	(28)
Net Postretirement Benefits Activity [Member] | Actuarial Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning, balance	(18,095)	(22,000)	(18,441)	(22,425)
Pre-tax Activity	563	700	1,126	1,400
Tax Effect	(218)	(274)	(435)	(549)
Ending, balance	(17,750)	(21,574)	(17,750)	(21,574)
Net Postretirement Benefits Activity [Member] | Prior Service Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning, balance	3,178	4,104	3,410	4,334
Pre-tax Activity	(378)	(378)	(756)	(756)
Tax Effect	145	148	291	296
Ending, balance	2,945	3,874	2,945	3,874
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning, balance	4	6	4	5
Pre-tax Activity	0	0	0	1
Tax Effect	0	0	0	0
Ending, balance	$ 4	$ 6	$ 4	$ 6