Amount of contributions made by the employer to defined benefit plans.

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Amount included in accumulated other comprehensive income (AOCI) related to gain (loss) expected to be recognized as components of net periodic benefit cost for the fiscal year that follows the most recent annual statement of financial position.

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Target allocation of investments of this type to total plan assets presented on a weighted average basis.

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Amount of employer's best estimate of contributions expected to be paid to the plan during the next fiscal year beginning after the date of the latest statement of financial position.

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The amount of the cost recognized during the period for defined contribution plans.

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Amount of the obligation recognized by withdrawing from a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

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Postretirement Benefits - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2016	Sep. 25, 2015	Sep. 26, 2014
Defined Benefit Plan Disclosure [Line Items]
Defined contribution plans expense	$ 2,817	$ 2,741	$ 3,162
Multi-employer Pension Plan
Multiemployer Plans [Line Items]
Liability	6,507	6,778
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss amortized from AOCL into net periodic benefit cost over next fiscal year	1,303
Employer contributions	411	$ 1,103
Estimated employer contributions in next fiscal year	$ 575
Pension Plan \| Equity securities
Defined Benefit Plan Disclosure [Line Items]
Policy target allocation	60.00%
Pension Plan \| Debt securities
Defined Benefit Plan Disclosure [Line Items]
Policy target allocation	40.00%