Accumulated Other Comprehensive Loss (Income) Related to Derivative Transactions (Detail) - USD ($) $ in Thousands		4 Months Ended
		Apr. 23, 2016	Apr. 25, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Net change in fair value of derivatives	[1]	$ 2,588	$ (4,428)
Closed Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Estimated amount of derivatives to be reclassified in income from AOCI		1,164
Closed Contracts | Commodity price risk derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Estimated amount of derivatives to be reclassified in income from AOCI		247
Closed Contracts | Interest rate risk derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Estimated amount of derivatives to be reclassified in income from AOCI		917
Expiring in 2016
Derivative Instruments, Gain (Loss) [Line Items]
Net change in fair value of derivatives		5,332
Expiring in 2016 | Commodity price risk derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Net change in fair value of derivatives		5,332
Expiring in 2017
Derivative Instruments, Gain (Loss) [Line Items]
Net change in fair value of derivatives		(37)
Expiring in 2017 | Commodity price risk derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Net change in fair value of derivatives		(37)
Closed or Expiring Over Next Three Years
Derivative Instruments, Gain (Loss) [Line Items]
Net change in fair value of derivatives		6,459
Closed or Expiring Over Next Three Years | Commodity price risk derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Net change in fair value of derivatives		5,542
Closed or Expiring Over Next Three Years | Interest rate risk derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Net change in fair value of derivatives		$ 917

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