Segment Information - Financial Information Related to Company's Reportable Segments (Detail) - USD ($) $ in Millions	3 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Net sales	$ 5,464	$ 5,305
Net sales	5,464	5,305
Segment EBITA	583	656
Corporate expenses	(136)	(138)
Amortization of intangible assets	(97)	(92)
Restructuring and impairment costs	0	(154)
Equity Securities, FV-NI, Unrealized Gain (Loss) Restricted	(21)	0
Net financing charges	(85)	(102)
Income from continuing operations before income taxes	244	170
Building Solutions North America
Segment Reporting Information [Line Items]
Net sales	2,116
Building Solutions EMEA/LA
Segment Reporting Information [Line Items]
Net sales	907
Building Solutions Asia Pacific
Segment Reporting Information [Line Items]
Net sales	613
Global Products
Segment Reporting Information [Line Items]
Net sales	1,828
Building Technologies & Solutions \| Building Solutions North America
Segment Reporting Information [Line Items]
Net sales	2,116	2,012
Segment EBITA	250	227
Building Technologies & Solutions \| Building Solutions EMEA/LA
Segment Reporting Information [Line Items]
Net sales	907	915
Segment EBITA	77	69
Building Technologies & Solutions \| Building Solutions Asia Pacific
Segment Reporting Information [Line Items]
Net sales	613	597
Segment EBITA	66	74
Building Technologies & Solutions \| Global Products
Segment Reporting Information [Line Items]
Net sales	1,828	1,781
Segment EBITA	$ 190	$ 286

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