Funded Status of Defined Benefit Pension and Post-Retirement Plans (Detail) - USD ($) $ in Thousands	Sep. 29, 2017	Sep. 30, 2016	Oct. 02, 2015
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 457,575	$ 425,781
Pension Plan \| Benefit Obligation
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations	(509,256)	(505,298)	$ (453,283)
Pension Plan \| Plan Assets - Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	457,575	425,781	389,461
Pension Plan \| Funded Status
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	457,575	425,781
Benefit obligations	(509,256)	(505,298)
Net amount recognized	(51,681)	(79,517)
Other Postretirement Benefit Plan \| Benefit Obligation
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations	(13,542)	(13,236)	(12,187)
Other Postretirement Benefit Plan \| Plan Assets - Fair Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0	$ 0
Other Postretirement Benefit Plan \| Funded Status
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Benefit obligations	(13,542)	(13,236)
Net amount recognized	$ (13,542)	$ (13,236)

Amount of actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Fair value of assets that have been segregated and restricted to provide pension or postretirement benefits. Assets include, but are not limited to, stocks, bonds, other investments, earnings from investments, and contributions by the employer and employees.

+ References

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- Definition

Amount of funded (unfunded) status of defined benefit plan, measured as difference between fair value of plan assets and benefit obligation. Includes, but is not limited to, overfunded (underfunded) status.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64852052&loc=d3e1703-114919

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