Employee Benefit Plans - Sensitivity Analysis (Detail) - Foreign Postretirement Benefits [Member] $ in Millions	12 Months Ended
Sep. 30, 2017 USD ($)
Defined Benefit Plan Disclosure [Line Items]
1 -Percent-Point Increase, Effect on postretirement benefit obligation	$ 3
1 -Percent-Point Decrease, Effect on postretirement benefit obligation	$ (3)

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.

No definition available.

+ Details

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- Definition

Amount of effect of a one-percentage-point decrease in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits.

+ 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 (m)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

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- Definition

The effect of a one-percentage-point increase in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits.

+ References

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