Share-Based Compensation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Share-Based Compensation (Textual) [Abstract]
Pre-tax share-based compensation expense	$ 26.8	$ 23.2	$ 51.0	$ 41.6
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants (in shares)			217	233
Weighted average share fair value (usd per share)			$ 85.91	$ 77.62
Performance shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants (in shares)			79	66
Weighted average share fair value (usd per share)			$ 295.06	$ 340.77
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants (in shares)			238	228
Weighted average share fair value (usd per share)			$ 276.36	$ 261.59
Unrestricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants (in shares)			6	7
Weighted average share fair value (usd per share)			$ 278.35	$ 261.72