Deferred Tax Liabilities and Assets (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 30, 2012	Dec. 25, 2011
Liabilities
Accelerated depreciation	$ 255,612	$ 295,391
Accelerated amortization of deductible intangibles	174,229	121,679
Other	26,989	29,890
Total deferred tax liabilities	456,830	446,960
Assets
Accrued compensation costs	77,684	97,532
Pension	368,803	346,000
Postretirement medical and life	65,573	71,674
Federal tax benefits of uncertain state tax positions	31,002	43,631
Partnership investments including impairments	39,542	52,344
Loss carryforwards	58,596	44,452
Other	66,164	77,035
Total deferred tax assets	707,364	732,668
Valuation allowance	76,419	54,287
Total net deferred tax assets	174,115	231,421
Net current deferred tax assets	15,840	22,771
Net long-term deferred tax assets	$ 158,275	$ 208,650