Effect of Derivative Instruments for Deferred Gains And (Losses) on Closed Contracts and Effective Portion in Fair Value on AOCI, Utilized for Risk Management Purposes (Detail) - USD ($) $ in Thousands		4 Months Ended
		Apr. 24, 2021	Apr. 18, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in AOCI on Derivatives(Effective Portion)	[1]	$ 4,745	$ (3,849)
Production costs		643,576	670,873
Income before income taxes		94,886	(7,791)
Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Income before income taxes	[2]	(220)	(411)
Interest Rate Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in AOCI on Derivatives(Effective Portion)	[1]	2,926
Interest Rate Contracts | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense	[2]	(164)	(33)
Commodity Contract
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in AOCI on Derivatives(Effective Portion)	[1]	1,819	(3,849)
Commodity Contract | Reclassification out of Accumulated Other Comprehensive Income | Product
Derivative Instruments, Gain (Loss) [Line Items]
Production costs	[2],[3]	$ (56)	$ (378)

[1] Amounts in parentheses indicate debits to determine net income.

[2] Amounts in parentheses, if any, indicate credits to determine net income.

[3] Included in materials, supplies, labor and other production costs (exclusive of depreciation and amortization shown separately).