Share-Based Compensation (Narrative) (Details)	6 Months Ended
	Mar. 31, 2026 $ / shares shares
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units/shares granted (in shares) | shares	100,048
Performance Shares, Internal Based
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value for time-based equity awards (in dollars per share) | $ / shares	$ 260.86
Performance Shares, Market Based
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value for time-based equity awards (in dollars per share) | $ / shares	$ 275.21
Time-Based Deferred Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units/shares granted (in shares) | shares	130,557
Weighted average grant date fair value for time-based equity awards (in dollars per share) | $ / shares	$ 260.73
LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grant | shares	600,000