Changes in Plan Assets and Benefit Obligations Recognized In Other Comprehensive Income (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 29, 2012	Dec. 31, 2011	Dec. 25, 2010
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive (income) loss at beginning of year	$ 548,212	$ 406,465
Net loss (gain)	7,610	159,118
Reduction due to settlement	(56,367)
Amortization of net loss	(17,954)	(17,371)	(13,239)
Accumulated other comprehensive (income) loss at end of year	481,501	548,212	406,465
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive (income) loss at beginning of year	(17,652)	(20,093)
Net loss (gain)	1,819	(1,334)
Amortization of net loss	(201)	(220)	(224)
Amortization of prior service credits	4,008	4,009	4,006
Canadian rate adjustment	52	(14)
Accumulated other comprehensive (income) loss at end of year	$ (11,974)	$ (17,652)	$ (20,093)

The pretax total of net gain (loss), prior service cost (credit), and transition assets (obligations), as well as minimum pension liability if still remaining, included in accumulated other comprehensive income associated with a defined benefit pension or other postretirement plan(s) because they have yet to be recognized as components of net periodic benefit cost.

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The amount of the prior service cost or credit recognized in net periodic benefit cost relating to benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation.

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Before tax amount, net of reclassification adjustments, of the (increase) decrease in the value of the projected benefit obligation and the increase (decrease) in the value of the plan assets resulting from experience different from that assumed or from a change in an actuarial assumption that has not been recognized in net periodic benefit cost.

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The amount of increase or decrease in plan assets attributed to foreign currency changes. The effects of foreign currency exchange rate changes that are to be disclosed are those applicable to plans of a foreign operation whose functional currency is not the reporting currency.

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Amount of net gain (loss) recognized in net periodic benefit cost as a result of an irrevocable action that relieves the employer (or the plan) of primary responsibility for a benefit obligation and eliminates significant risks related to the obligation and the assets used to effect the settlement. Examples of transactions that constitute a settlement include, but are not limited to, lump-sum cash payments to plan participants in exchange for their rights to receive specified benefits and purchasing nonparticipating annuity contracts to cover vested benefits.

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Net of tax amount of the income statement impact of the reclassification adjustment for actuarial (gains) losses recognized as a component of net periodic benefit cost.

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