RETIREMENT MEDICAL PLANS (Details 6) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2015	Sep. 30, 2014
Retiree Medical Plan Effect Of One Percentage Point Change In Assumed Health Care Cost Trend Rates [Abstract]
Effect on total service and interest cost 1% increase	$ 2	$ 2
Effect on total service and interest cost 1% decrease	(1)	(2)
Effect on APBO 1% increase	39	46
Effect on APBO 1% decrease	$ (34)	$ (40)

Retiree Medical Plan Effect Of One Percentage Point Change In Assumed Health Care Cost Trend Rates.

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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=58740216&loc=d3e1928-114920

+ 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 aggregate of the service and interest cost components of net periodic postretirement health care benefit costs.

+ References

+ Details

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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

+ Details

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- Definition

The effect of a one-percentage-point increase in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs.

+ References

+ Details

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