Loss Reclassified From AOCI for Commodity Contracts (Detail) - USD ($) $ in Thousands		4 Months Ended
		Apr. 21, 2018	Apr. 22, 2017
Accumulated Other Comprehensive Income Loss [Line Items]
Net of tax		$ 297	$ 474
Gains/Losses on Cash Flow Hedges
Accumulated Other Comprehensive Income Loss [Line Items]
Gross loss reclassified from AOCI into income	[1]	397	771
Tax benefit	[1]	(100)	(297)
Net of tax	[1]	297	474
Commodity Contract | Gains/Losses on Cash Flow Hedges
Accumulated Other Comprehensive Income Loss [Line Items]
Gross loss reclassified from AOCI into income	[1],[2]	353	727
Tax benefit		(89)	(280)
Net of tax		$ 264	$ 447

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

[2] Amounts are presented as an adjustment to reconcile net income (loss) to net cash provided by operating activities on the Condensed Consolidated Statements of Cash Flows.