Reclassifications Out of Accumulated Other Comprehensive Loss (Detail) (USD $) In Thousands, unless otherwise specified	4 Months Ended
	Apr. 20, 2013	Apr. 21, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain and loss on cash flow hedges reclassified from AOCI into Income	$ (1,637)
Tax (expense) or benefit	(630)
Total net of tax	(1,007)	(10,036)
Prior-service credits	79
Actuarial losses	(1,655)
Total before tax	(1,576)
Tax (expense) or benefit	(607)
Total net of tax	(969)
Total reclassifications	(1,976)
Interest Rate Contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain and loss on cash flow hedges reclassified from AOCI into Income	(542)
Commodity Contract
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain and loss on cash flow hedges reclassified from AOCI into Income	$ (1,095)