Income Taxes - Schedule of Income Tax Data (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Components of Income before income taxes
United States	$ 388.3	$ 794.2	$ 371.3
Non-United States	710.8	814.3	702.3
Income before income taxes	1,099.1	1,608.5	1,073.6
Components of Income tax provision
United States	78.3	221.3	71.6
Non-United States	127.6	160.6	102.9
State and local	14.0	48.7	13.6
Total current	219.9	430.6	188.1
Deferred
United States	(42.1)	(84.6)	(10.7)
Non-United States	(11.8)	6.0	(13.0)
State and local	(14.2)	(21.5)	(9.9)
Total deferred	(68.1)	(100.1)	(33.6)
Income tax provision	151.8	330.5	154.5
Total income taxes paid	$ 478.6	$ 344.9	$ 340.2