Accumulated Other Comprehensive Loss - Summary of Accumulated Other Comprehensive Loss (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning, balance	$ (58,176)	$ (94,526)	$ (80,820)
Gains (Losses) During the Period, Pre-tax Activity	(54,248)	42,725	(26,267)
Gains (Losses) During the Period, Tax Effect	20,939	(16,491)	10,338
Reclassification to income, Pre-tax Activity	2,559	16,499	3,665
Reclassification to income, Tax Effect	(988)	(6,383)	(1,442)
Ending, balance	(89,914)	(58,176)	(94,526)
Net Pension Activity [Member] | Actuarial Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning, balance	(43,028)	(76,407)	(64,789)
Gains (Losses) During the Period, Pre-tax Activity	(53,597)	39,337	(21,979)
Gains (Losses) During the Period, Tax Effect	20,688	(15,183)	8,651
Reclassification to income, Pre-tax Activity	1,743	15,041	2,822
Reclassification to income, Tax Effect	(673)	(5,816)	(1,112)
Ending, balance	(74,867)	(43,028)	(76,407)
Net Pension Activity [Member] | Prior Service Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning, balance	(121)	(33)	(44)
Gains (Losses) During the Period, Pre-tax Activity	0	(171)	0
Gains (Losses) During the Period, Tax Effect	0	66	0
Reclassification to income, Pre-tax Activity	36	28	17
Reclassification to income, Tax Effect	(14)	(11)	(6)
Ending, balance	(99)	(121)	(33)
Net Postretirement Benefits Activity [Member] | Actuarial Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning, balance	(18,441)	(22,425)	(21,244)
Gains (Losses) During the Period, Pre-tax Activity	(9,324)	3,560	(4,287)
Gains (Losses) During the Period, Tax Effect	3,598	(1,374)	1,687
Reclassification to income, Pre-tax Activity	2,293	2,943	2,339
Reclassification to income, Tax Effect	(885)	(1,145)	(920)
Ending, balance	(22,759)	(18,441)	(22,425)
Net Postretirement Benefits Activity [Member] | Prior Service Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning, balance	3,410	4,334	5,251
Gains (Losses) During the Period, Pre-tax Activity	8,682	0	0
Gains (Losses) During the Period, Tax Effect	(3,351)	0	0
Reclassification to income, Pre-tax Activity	(1,513)	(1,513)	(1,513)
Reclassification to income, Tax Effect	584	589	596
Ending, balance	7,812	3,410	4,334
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning, balance	4	5	6
Gains (Losses) During the Period, Pre-tax Activity	(9)	(1)	(1)
Gains (Losses) During the Period, Tax Effect	4	0	0
Reclassification to income, Pre-tax Activity	0	0	0
Reclassification to income, Tax Effect	0	0	0
Ending, balance	$ (1)	$ 4	$ 5