Accumulated Other Comprehensive Loss (Schedule of Reclassifications out of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
OCI Cash flow hedges reclass to earnings, before tax	$ (0.2)	$ 2.0	$ 1.5	$ 4.4
Reclassifications to earnings			(0.2)	2.2
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
OCI Cash flow hedges reclass to earnings, before tax	(0.2)	2.0
OCI Cash flow hedge, reclassification to earnings, tax	(0.1)	0.6	0.4	1.4
Other comprehensive income, reclassification to earnings, cash flow hedges, after tax	(0.1)	1.4	1.1	3.0
Amortization of defined benefit pension and postretirement items, actuarial losses, before tax	(0.6)	(0.4)	(1.8)	(1.1)
Amortization of defined benefit pension and postretirement items, tax	(0.2)	(0.2)	(0.5)	(0.3)
Amortization of defined benefit pension and postretirement items, after tax	(0.4)	(0.2)	(1.3)	(0.8)
Reclassifications to earnings	$ (0.5)	$ 1.2	$ (0.2)	$ 2.2