Business Segments Geographic Information (Details) - USD ($) $ in Millions	3 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Net sales	$ 4,161	$ 4,151
Reportable Geographical Components [Member]
Disaggregation of Revenue [Line Items]
Net sales	4,168	4,155
Reportable Geographical Components [Member] \| Americas
Disaggregation of Revenue [Line Items]
Net sales	2,149	2,273
Reportable Geographical Components [Member] \| Asia, Middle East & Africa
Disaggregation of Revenue [Line Items]
Net sales	1,250	1,173
Reportable Geographical Components [Member] \| Europe [Member]
Disaggregation of Revenue [Line Items]
Net sales	769	709
Reportable Geographical Components [Member] \| Automation Solutions [Member]
Disaggregation of Revenue [Line Items]
Net sales	2,692	2,852
Reportable Geographical Components [Member] \| Automation Solutions [Member] \| Americas
Disaggregation of Revenue [Line Items]
Net sales	1,168	1,410
Reportable Geographical Components [Member] \| Automation Solutions [Member] \| Asia, Middle East & Africa
Disaggregation of Revenue [Line Items]
Net sales	942	896
Reportable Geographical Components [Member] \| Automation Solutions [Member] \| Europe [Member]
Disaggregation of Revenue [Line Items]
Net sales	582	546
Reportable Geographical Components [Member] \| Commercial & Residential Solutions [Member]
Disaggregation of Revenue [Line Items]
Net sales	1,476	1,303
Reportable Geographical Components [Member] \| Commercial & Residential Solutions [Member] \| Americas
Disaggregation of Revenue [Line Items]
Net sales	981	863
Reportable Geographical Components [Member] \| Commercial & Residential Solutions [Member] \| Asia, Middle East & Africa
Disaggregation of Revenue [Line Items]
Net sales	308	277
Reportable Geographical Components [Member] \| Commercial & Residential Solutions [Member] \| Europe [Member]
Disaggregation of Revenue [Line Items]
Net sales	$ 187	$ 163

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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-Section S99
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+ Details