Retirement Plans - Changes in Plan Assets and Benefit Obligations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Changes recognized in accumulated other comprehensive loss:
Net amount recognized	$ (16,171)	$ 44,985	$ (83,663)
Pension Benefits [Member]
Changes recognized in accumulated other comprehensive loss:
Actuarial gain (loss)	523	(64,296)	(3,171)
Curtailment	138		73,191
Prior year correction		(21,917)
Amortization of net loss (gain)	3,848	8,255	10,394
Amortization of prior service cost (credit)	138	157	195
Amortization of net loss (gain)	3,848	8,255	10,394
Settlements	17,785	4,487	3,358
Net amount recognized	22,432	(73,314)	83,967
Other Postretirement Plans [Member]
Changes recognized in accumulated other comprehensive loss:
Actuarial gain (loss)	181	(174)	1,035
Prior service cost			(1,291)
Amortization of net loss (gain)	(148)	(71)	14
Amortization of prior service cost (credit)	6	6	(62)
Amortization of net loss (gain)	(148)	(71)	14
Net amount recognized	$ 39	$ (239)	$ (304)