Effect of Derivative Instruments Located on the Condensed Consolidated Statements of Income, Utilized for Risk Management Purposes (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jul. 16, 2016	Jul. 18, 2015	Jul. 16, 2016	Jul. 18, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)(Net of tax)	[1]	$ 3,525	$ (5,818)	$ 937	$ (1,390)
Production costs		477,955	457,253	1,099,145	1,043,169
Income before income taxes		78,425	79,181	170,803	174,137
Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Income before income taxes	[1]	(803)	(1,251)	(1,946)	(2,838)
Interest Rate Contracts | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Interest (expense) income	[1]	(35)	(35)	(82)	(82)
Commodity Contract
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)(Net of tax)	[1]	3,525	(5,818)	937	(1,390)
Commodity Contract | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Production costs	[1],[2]	$ (768)	$ (1,216)	$ (1,864)	$ (2,756)

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

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