Share-Based Compensation (Narrative) (Details)	6 Months Ended
	Mar. 31, 2024 $ / shares shares
Market-Based Deferred Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units/shares granted	102,120
Performance period	3 years
Weighted average grant date fair value (in dollars per unit/share) | $ / shares	$ 302.10
Time-Based Deferred Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units/shares granted	139,425
Weighted average grant date fair value (in dollars per unit/share) | $ / shares	$ 272.05
LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grant	1,000,000.0