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, 2023		Jun. 30, 2022		Jun. 30, 2023	Jun. 30, 2022
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of defined benefit pension and postretirement items, settlement loss, before tax	$ 0.0				$ (7.2)
Reclassifications to earnings					(1.5)	$ 0.8
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	1.0		$ 3.4
OCI Cash flow hedge, reclassification to earnings, tax	0.3		1.1		2.1	2.1
Other comprehensive income, reclassification to earnings, cash flow hedges, after tax	0.7		2.3		4.7	4.2
Amortization of defined benefit pension and postretirement items, actuarial losses, before tax	(0.4)	[1]	(1.5)	[1]	(1.2)	(4.6)
Amortization of defined benefit pension and postretirement items, tax	(0.1)		(0.4)		(2.2)	(1.2)
Amortization of defined benefit pension and postretirement items, after tax	(0.3)		(1.1)		(6.2)	(3.4)
Reclassifications to earnings	$ 0.4		$ 1.2		$ (1.5)	$ 0.8

[1] These AOCI components are included in the computation of net periodic cost. See Note 11 of Notes to Condensed Consolidated Financial Statements.