Comprehensive Income (Loss) - Additional Information (Detail) (USD $)	3 Months Ended				9 Months Ended
	Oct. 06, 2012		Oct. 08, 2011		Oct. 06, 2012		Oct. 08, 2011
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total comprehensive income	$ 34,600,000		$ 21,200,000		$ 119,400,000		$ 61,600,000
Amounts reclassified out of accumulated other comprehensive loss to net income, Gross					(24,972,000)		40,354,000
Amounts reclassified out of accumulated other comprehensive loss to net income, Deferred Tax Adjustment					10,478,000
Amounts reclassified out of accumulated other comprehensive loss to net income, Net of Tax	(2,677,000)		2,054,000		(16,737,000)		22,894,000
Commodity Contract
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified out of accumulated other comprehensive loss to net income, Deferred Tax Adjustment					9,600,000
Commodity Contract | Production Costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified out of accumulated other comprehensive loss to net income, Net of Tax	$ (2,299,000)	[1]	$ 2,605,000	[1]	$ (15,358,000)	[1]	$ 24,817,000	[1]

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