Segment Information - Financial Information Related to Company's Reportable Segments (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Net sales	$ 9,516	$ 9,608	$ 27,476	$ 28,430
Segment Income	836	822	2,225	2,208
Restructuring and impairment costs	102	0	331	0
Net financing charges	(69)	(75)	(211)	(215)
Income from continuing operations before income taxes	665	747	1,683	1,993
Power Solutions
Segment Reporting Information [Line Items]
Net sales	1,519	1,473	4,842	4,905
Segment Income	261	234	867	813
Building Efficiency
Segment Reporting Information [Line Items]
Net sales	3,635	2,733	9,741	7,607
Segment Income	369	260	757	583
Building Efficiency \| Building Efficiency Products North America
Segment Reporting Information [Line Items]
Net sales	690	670	1,793	1,773
Segment Income	75	91	119	184
Building Efficiency \| Building Efficiency Systems and Service North America
Segment Reporting Information [Line Items]
Net sales	1,113	1,086	3,131	3,002
Segment Income	122	100	303	248
Building Efficiency \| Building Efficiency Asia
Segment Reporting Information [Line Items]
Net sales	1,361	500	3,515	1,429
Segment Income	157	52	321	127
Building Efficiency \| Building Efficiency Rest of World [Member]
Segment Reporting Information [Line Items]
Net sales	471	477	1,302	1,403
Segment Income	15	17	14	24
Automotive Experience
Segment Reporting Information [Line Items]
Net sales	4,362	5,402	12,893	15,918
Segment Income	206	328	601	812
Automotive Experience \| Seating
Segment Reporting Information [Line Items]
Net sales	4,251	4,255	12,514	12,531
Segment Income	188	273	538	703
Automotive Experience \| Interiors
Segment Reporting Information [Line Items]
Net sales	111	1,147	379	3,387
Segment Income	$ 18	$ 55	$ 63	$ 109

Net financing charges includes interest expense, interest income, bank fees and amortization of debt issuance costs.

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- Definition

Amount of income or loss from continuing operations for the reportable segment before income taxes and noncontrolling interests, excluding net financing charges, significant restructuring and impairment costs, and net mark-to-market adjustments on pension and postretirement plans.

+ References

No definition available.

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- Definition

This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, extraordinary items, and noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 940
-SubTopic 20
-Section 25
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=51673353&loc=d3e41242-110953

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-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 10
-Article 5

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- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
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-Name Accounting Standards Codification
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-Name Staff Accounting Bulletin (SAB)
-Number Topic 5
-Section P
-Subsection 3, 4

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- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
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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.

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