Business Segments (Details) - USD ($) $ in Millions	3 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Net sales	$ 4,473	$ 4,161
Earnings	1,175	563
Interest expense	(38)	(40)
Gain from periodic distribution from retained subordinated interest in Vertiv (VRT)	(453)	0
Operating Segments [Member] \| Automation Solutions [Member]
Segment Reporting Information [Line Items]
Net sales	2,805	2,692
Earnings	526	361
Operating Segments [Member] \| Commercial & Residential Solutions [Member]
Segment Reporting Information [Line Items]
Net sales	1,671	1,476
Earnings	299	310
Operating Segments [Member] \| Climate Technologies [Member]
Segment Reporting Information [Line Items]
Net sales	1,163	1,031
Earnings	192	212
Operating Segments [Member] \| Tools & Home Products [Member]
Segment Reporting Information [Line Items]
Net sales	508	445
Earnings	107	98
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Stock compensation	(41)	(64)
Unallocated pension and postretirement costs	26	24
Interest expense	(38)	(40)
Corporate and other [Member]
Segment Reporting Information [Line Items]
Earnings	(50)	(28)
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	$ (3)	$ (7)

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