Summary of Reclassifications Out of AOCI (Detail) - USD ($) $ in Thousands		4 Months Ended
		Apr. 21, 2018	Apr. 22, 2017
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, Gains and losses on cash flow hedges net of tax		$ (297)	$ (474)
Reclassification From AOCI, Current Period Net Of Tax	[1]	(4,889)	(1,617)
Gains/Losses on Cash Flow Hedges
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, Gains and losses on cash flow hedges before tax	[1]	(397)	(771)
Reclassification from AOCI, Gains and losses on cash flow hedges tax benefit	[1]	100	297
Reclassification from AOCI, Gains and losses on cash flow hedges net of tax	[1]	(297)	(474)
Reclassification From AOCI, Current Period Net Of Tax		(297)	(474)
Amortization of defined benefit pension items, prior service costs
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, Current Period, before Tax	[1],[2]	(35)	(54)
Amortization of defined benefit pension items, settlement losses
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, Current Period, before Tax	[1],[2]	(4,668)
Amortization of defined benefit pension items, actuarial losses
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, Current Period, before Tax	[1],[2]	(1,440)	(1,805)
Accumulated Defined Benefit Plans Adjustment
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, Current Period, before Tax	[1]	(6,143)	(1,859)
Reclassification from AOCI, Current Period, Tax benefit	[1]	1,551	716
Reclassification From AOCI, Current Period Net Of Tax	[1]	(4,592)	(1,143)
Interest Rate Contracts | Gains/Losses on Cash Flow Hedges
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, Gains and losses on cash flow hedges before tax	[1]	(44)	(44)
Commodity Contract | Gains/Losses on Cash Flow Hedges
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, Gains and losses on cash flow hedges before tax	[1],[3]	(353)	(727)
Reclassification from AOCI, Gains and losses on cash flow hedges tax benefit		89	280
Reclassification from AOCI, Gains and losses on cash flow hedges net of tax		$ (264)	$ (447)

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

[2] These items are included in the computation of net periodic pension cost. These are reported in the other components of net periodic pension and postretirement benefits credit line item on the Condensed Consolidated Statements of Operations. See Note 18, Postretirement Plans, of Notes to Condensed Consolidated Financial Statements of this Form 10-Q for additional information.

[3] 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.