Derivative Instruments Located on Consolidated Statements of Income (Detail) (USD $) In Thousands, unless otherwise specified	4 Months Ended
	Apr. 20, 2013		Apr. 21, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in OCI on Derivative (Effective Portion)(Net of tax)	$ (8,621)		$ (7,009)
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)(Net of tax)	(1,007)		(10,036)
Amount of (Gain) or Loss Recognized from Accumulated OCI into Income (Ineffective Portion And Amount Excluded From Effectiveness Testing Net)			(627)
Interest Rate Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in OCI on Derivative (Effective Portion)(Net of tax)	(296)		(1,548)
Interest Rate Contracts | Selling, General and Administrative Expenses
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (Gain) or Loss Recognized from Accumulated OCI into Income (Ineffective Portion And Amount Excluded From Effectiveness Testing Net)			(627)
Interest Rate Contracts | Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)(Net of tax)	(334)		(590)
Commodity Contract
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in OCI on Derivative (Effective Portion)(Net of tax)	(8,325)		(5,461)
Commodity Contract | Production Costs
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)(Net of tax)	$ (673)	[1]	$ (9,446)	[1]

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