Business Segment Information - Sales and Operating Results (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Sep. 30, 2021
Sales and operating results of reportable segments
Sales	$ 1,968.7		$ 1,848.2	$ 5,634.1	$ 5,189.6
Purchase accounting depreciation and amortization	(25.9)		(12.9)	(78.1)	(37.7)
Corporate and other	(15.6)		(29.2)	(69.6)	(87.6)
Non-operating pension and postretirement benefit credit (cost)	11.9		(34.3)	(5.0)	(48.3)
Change in fair value of investments	(5.2)		43.3	(138.3)	624.6
Legal settlement	0.0		0.0	0.0	70.0
Interest expense, net	(30.2)		(22.1)	(88.9)	(67.2)
Income before income taxes	344.2		313.5	667.8	1,521.9
Gain (loss) related to litigation settlement		$ 70.0				$ 70.0
Operating Segments
Sales and operating results of reportable segments
Segment operating earnings	409.2		368.7	1,047.7	1,068.1
Intelligent Devices
Sales and operating results of reportable segments
Sales	878.3		882.9	2,587.2	2,454.8
Intelligent Devices | Operating Segments
Sales and operating results of reportable segments
Segment operating earnings	173.2		193.6	504.4	535.8
Software & Control
Sales and operating results of reportable segments
Sales	606.9		509.6	1,655.7	1,452.9
Software & Control | Operating Segments
Sales and operating results of reportable segments
Segment operating earnings	190.6		128.3	439.7	411.2
Lifecycle Services
Sales and operating results of reportable segments
Sales	483.5		455.7	1,391.2	1,281.9
Lifecycle Services | Operating Segments
Sales and operating results of reportable segments
Segment operating earnings	$ 45.4		$ 46.8	$ 103.6	$ 121.1