Retirement Plans - Changes in Plan Assets and Benefit Obligations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 27, 2014
Changes recognized in other comprehensive loss:
Net amount recognized	$ 44,985	$ (83,663)	$ 155,362
Pension Benefits [Member]
Changes recognized in other comprehensive loss:
Actuarial (loss) gain	(64,296)	(3,171)	(160,345)
Curtailment		73,191
Prior year correction	(21,917)
Amortization of prior service cost (credit)	157	195	198
Amortization of net loss (gain)	8,255	10,394	2,294
Settlements	4,487	3,358	2,370
Net amount recognized	(73,314)	83,967	(155,483)
Other Postretirement Plans [Member]
Changes recognized in other comprehensive loss:
Actuarial (loss) gain	(174)	1,035	(986)
Curtailment			(2,096)
Prior service (cost) credit		(1,291)	3,612
Amortization of prior service cost (credit)	6	(62)	(334)
Amortization of net loss (gain)	(71)	14	(75)
Net amount recognized	$ (239)	$ (304)	$ 121