Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands	4 Months Ended
	Apr. 20, 2024	Apr. 22, 2023
Pension plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 224	$ 210
Interest cost	362	401
Expected return on plan assets	(494)	(480)
Amortization of prior service cost (credit)	18	18
Amortization of net (gain) loss	13	53
Total net periodic pension cost (credit)	123	202
Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	56	55
Interest cost	70	73
Amortization of prior service cost (credit)	(72)	(72)
Amortization of net (gain) loss	(55)	(76)
Total net periodic pension cost (credit)	$ (1)	$ (20)