Income Taxes - Schedule of Income Tax Data (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Components of Income before income taxes
United States	$ 280.0	$ 389.0	$ 794.0
Non-United States	637.0	711.0	814.0
Income before income taxes	917.0	1,100.0	1,608.0
Components of Income tax provision
United States	97.0	78.0	221.0
Non-United States	169.0	128.0	160.0
State and local	16.0	14.0	49.0
Total current	282.0	220.0	430.0
Deferred
United States	(87.0)	(42.0)	(85.0)
Non-United States	(11.0)	(12.0)	6.0
State and local	(16.0)	(14.0)	(21.0)
Total deferred	(114.0)	(68.0)	(100.0)
Income tax provision	168.0	152.0	330.0
Total income taxes paid	$ 356.0	$ 479.0	$ 345.0