Components of Net Periodic Benefit (Income) Cost (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 15, 2017	Jul. 16, 2016	Jul. 15, 2017	Jul. 16, 2016
Pension plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 174	$ 192	$ 407	$ 447
Interest cost	3,006	2,884	7,013	7,417
Expected return on plan assets	(5,895)	(5,457)	(13,754)	(14,069)
Settlement loss		4,641		4,641
Amortization of prior service cost (credit)	89	76	208	195
Amortization of net (gain) loss	1,469	1,155	3,427	2,953
Total net periodic benefit (income) cost	(1,157)	3,491	(2,699)	1,584
Post-retirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	59	93	138	216
Interest cost	52	71	122	166
Amortization of prior service cost (credit)	(49)	(49)	(114)	(114)
Amortization of net (gain) loss	(114)	(105)	(268)	(245)
Total net periodic benefit (income) cost	$ (52)	$ 10	$ (122)	$ 23