Share-Based Compensation (Market-Based Deferred Stock Unit Valuation Assumptions) (Details) - Market-Based Deferred Stock Unit	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	30.30%	25.00%	32.50%
Risk-free interest rate	4.10%	4.30%	4.00%
Expected dividend yield	2.10%	2.60%	2.40%