Segment Information - Financial Information Related to Company's Reportable Segments (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Segment Reporting Information [Line Items]
Net sales	$ 9,031	$ 9,198	$ 17,960	$ 18,822
Segment Income	702	680	1,389	1,386
Restructuring and impairment costs	229	0	229	0
Net financing charges	(74)	(69)	(142)	(140)
Income from continuing operations before income taxes	399	611	1,018	1,246
Power Solutions
Segment Reporting Information [Line Items]
Net sales	1,583	1,588	3,323	3,432
Segment Income	264	264	606	579
Building Efficiency
Segment Reporting Information [Line Items]
Net sales	3,150	2,377	6,106	4,874
Segment Income	221	166	388	323
Building Efficiency \| Building Efficiency Products North America
Segment Reporting Information [Line Items]
Net sales	546	545	1,103	1,103
Segment Income	27	49	44	93
Building Efficiency \| Building Efficiency Systems and Service North America
Segment Reporting Information [Line Items]
Net sales	1,034	959	2,018	1,916
Segment Income	88	84	181	148
Building Efficiency \| Building Efficiency Asia
Segment Reporting Information [Line Items]
Net sales	1,162	428	2,154	929
Segment Income	102	26	164	75
Building Efficiency \| Building Efficiency Rest of World [Member]
Segment Reporting Information [Line Items]
Net sales	408	445	831	926
Segment Income	4	7	(1)	7
Automotive Experience
Segment Reporting Information [Line Items]
Net sales	4,298	5,233	8,531	10,516
Segment Income	217	250	395	484
Automotive Experience \| Seating
Segment Reporting Information [Line Items]
Net sales	4,177	4,141	8,263	8,276
Segment Income	184	229	350	430
Automotive Experience \| Interiors
Segment Reporting Information [Line Items]
Net sales	121	1,092	268	2,240
Segment Income	$ 33	$ 21	$ 45	$ 54

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
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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
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-Name Accounting Standards Codification
-Topic 230
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-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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