Tax Effect of Temporary Differences of Deferred Tax Assets and Deferred Tax Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 29, 2012	Dec. 31, 2011
Deferred tax assets:
Self-insurance reserves	$ 116,901	$ 114,522
Retirement plan contributions	49,876	48,825
Postretirement benefit cost	46,688	41,515
Reserves not currently deductible	15,986	18,047
Inventory capitalization	11,768	11,687
Other	23,045	18,642
Total deferred tax assets	264,264	253,238
Deferred tax liabilities:
Property, plant and equipment, primarily due to depreciation	497,932	491,485
Investment valuation	24,086	7,831
Other	11,706	11,324
Total deferred tax liabilities	$ 533,724	$ 510,640