Business Segment Information - Sales and Operating Results (Details) - USD ($) $ in Millions	3 Months Ended
Dec. 31, 2024	Dec. 31, 2023
Sales and operating results of reportable segments
Sales	$ 1,881.0	$ 2,052.0
Purchase accounting depreciation and amortization	(35.0)	(36.0)
Corporate and other	(38.0)	(40.0)
Non-operating pension and postretirement benefit credit	0.0	5.0
Change in fair value of investments	0.0	3.0
Interest expense, net	(35.0)	(28.0)
Income before income taxes	213.0	260.0
Operating Segments
Sales and operating results of reportable segments
Segment operating earnings	321.0	356.0
Intelligent Devices
Sales and operating results of reportable segments
Sales	806.0	927.0
Intelligent Devices \| Operating Segments
Sales and operating results of reportable segments
Segment operating earnings	120.0	150.0
Software & Control
Sales and operating results of reportable segments
Sales	529.0	604.0
Software & Control \| Operating Segments
Sales and operating results of reportable segments
Segment operating earnings	133.0	151.0
Lifecycle Services
Sales and operating results of reportable segments
Sales	546.0	521.0
Lifecycle Services \| Operating Segments
Sales and operating results of reportable segments
Segment operating earnings	$ 68.0	$ 55.0

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