Schedule of Reconciliation of Benefit Obligations, Plan Assets, Funded Status, and Related Actuarial Assumptions (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Sep. 29, 2012	Sep. 24, 2011	Sep. 25, 2010
Pension And Other Employee Benefit Plans [Line Items]
Benefit obligation at beginning of year	$ (8,064)	$ (9,093)	$ (6,736)
Service cost
Interest cost	(391)	(389)	(401)
Plan participants' contributions
Actuarial gain (loss)	(2,002)	1,092	(2,814)
Foreign exchange	383	(5)	541
Benefits paid	330	331	317
Benefit obligation at end of year	(9,744)	(8,064)	(9,093)
Plan assets
Funded status	$ (9,744)	$ (8,064)	$ (9,093)

Defined Benefit Plan Actuarial Net Gains Losses Net Of Tax Amount

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1) For defined benefit pension plans, the benefit obligation is the projected benefit obligation, which is the actuarial present value as of a date of all benefits attributed by the pension benefit formula to employee service rendered prior to that date. 2) For other postretirement defined benefit plans, the benefit obligation is the accumulated postretirement benefit obligation, which is the actuarial present value of benefits attributed to employee service rendered to a particular date.

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The amount of payments made for which participants are entitled under a pension plan, including pension benefits, death benefits, and benefits due on termination of employment. Also includes payments made under a postretirement benefit plan, including prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services. This item represents a periodic decrease to the plan obligations and a decrease to plan assets.

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The amount of contributions made by plan participants. This item represents a periodic increase to the plan obligation and an increase to plan assets.

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Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets.

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Amount of gain (loss) from foreign currency exchange rate changes for benefit obligation for plans of a foreign operation whose functional currency is not the reporting currency.

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The funded status is measured as the difference between the fair value of plan assets and the benefit obligation. Will normally be the same as the net Defined Benefit Plan, Amounts Recognized in Balance Sheet, Total.

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The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time.

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The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the plan.

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