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

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Amount of income or loss from continuing operations before income taxes and noncontrolling interests, excluding general corporate expenses, intangible asset amortization, net financing charges, significant restructuring and impairment costs, and net mark-to-market adjustments on pension and postretirement plans.

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The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Amount of gain (loss) related to change in benefit obligation resulting from changes in actuarial assumptions, for example, but not limited to, interest, mortality, employee turnover, salary, and temporary deviation from the substantive plan.

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Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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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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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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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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Segment Information - Financial Information Related to Company's Reportable Segments (Detail) - USD ($) $ in Millions	3 Months Ended					9 Months Ended
	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Information [Line Items]
Net sales	$ 7,683			$ 5,154		$ 22,036	$ 14,583
Segment EBITA	1,216			720		2,996	1,837
Corporate expenses	(172)			(126)		(605)	(323)
Amortization of intangible assets	(108)			(22)		(383)	(62)
Restructuring and impairment costs	(49)	$ (99)	$ (78)	(27)	$ (60)	(226)	(87)
Net mark-to-market adjustments on pension plans	(45)			0		90	0
Net financing charges	(124)			(65)		(376)	(202)
Income from continuing operations before income taxes	718			480		1,496	1,163
Power Solutions
Segment Reporting Information [Line Items]
Net sales	1,609			1,519		5,205	4,842
Segment EBITA	304			280		996	922
Building Technologies & Solutions [Member]
Segment Reporting Information [Line Items]
Net sales	6,074			3,635		16,831	9,741
Segment EBITA	912			440		2,000	915
Building Technologies & Solutions [Member] \| Building Efficiency Systems and Service North America
Segment Reporting Information [Line Items]
Net sales	1,128			1,113		3,103	3,131
Segment EBITA	126			142		291	342
Building Technologies & Solutions [Member] \| Building Efficiency Products North America
Segment Reporting Information [Line Items]
Net sales	698			690		1,826	1,793
Segment EBITA	98			96		192	176
Building Technologies & Solutions [Member] \| Building Efficiency Asia
Segment Reporting Information [Line Items]
Net sales	1,456			1,361		3,671	3,515
Segment EBITA	246			180		483	368
Building Technologies & Solutions [Member] \| Building Efficiency Rest of World [Member]
Segment Reporting Information [Line Items]
Net sales	456			471		1,278	1,302
Segment EBITA	26			22		25	29
Building Technologies & Solutions [Member] \| Building Technologies & Solutions Tyco [Member]
Segment Reporting Information [Line Items]
Net sales	2,336			0		6,953	0
Segment EBITA	416			0		1,009	0
Building Efficiency
Segment Reporting Information [Line Items]
Net sales	3,738			3,635		9,878	9,741
Segment EBITA	$ 496			$ 440		$ 991	$ 915