Business Segment Information - Sales and Operating Results (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Sales and operating results of reportable segments
Sales	$ 2,238.7	$ 1,968.7	$ 6,495.1	$ 5,634.1
Purchase accounting depreciation and amortization	(27.2)	(25.9)	(79.8)	(78.1)
Corporate and other	(32.3)	(15.6)	(88.8)	(69.6)
Non-operating pension and postretirement credit (cost)	5.5	11.9	(87.5)	(5.0)
Change in fair value of investments	85.7	(5.2)	289.3	(138.3)
Interest expense, net	(32.9)	(30.2)	(100.2)	(88.9)
Income before income taxes	471.8	344.2	1,291.1	667.8
Operating Segments
Sales and operating results of reportable segments
Segment operating earnings	473.0	409.2	1,358.1	1,047.7
Intelligent Devices
Sales and operating results of reportable segments
Sales	968.1	878.3	2,927.5	2,587.2
Intelligent Devices | Operating Segments
Sales and operating results of reportable segments
Segment operating earnings	163.1	173.2	579.4	504.4
Software & Control
Sales and operating results of reportable segments
Sales	750.6	606.9	2,065.0	1,655.7
Software & Control | Operating Segments
Sales and operating results of reportable segments
Segment operating earnings	261.5	190.6	678.1	439.7
Lifecycle Services
Sales and operating results of reportable segments
Sales	520.0	483.5	1,502.6	1,391.2
Lifecycle Services | Operating Segments
Sales and operating results of reportable segments
Segment operating earnings	$ 48.4	$ 45.4	$ 100.6	$ 103.6