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, 2021		Jun. 30, 2020		Jun. 30, 2021	Jun. 30, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications to earnings					$ (7.6)	$ (3.6)
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gains and losses on cash flow hedges, foreign exchange contracts, before tax	$ (0.5)		$ 1.0		(3.7)	2.6
Gains and losses on cash flow hedges, foreign exchange contracts, tax	(0.1)		0.3		(1.1)	0.8
Gains and losses on cash flow hedges, foreign exchange contracts, after tax	(0.4)		0.7		(2.6)	1.8
Amortization of defined benefit pension and postretirement items, actuarial losses, before tax	(2.4)	[1]	(2.2)	[1]	(7.0)	(6.8)
Amortization of defined benefit pension and postretirement items, settlement loss, before tax	0.0		0.3		0.0	0.7
Amortization of defined benefit pension and postretirement items, before tax	(2.4)		(2.5)		(7.0)	(7.5)
Amortization of defined benefit pension and postretirement items, tax	(0.7)		(0.7)		(2.0)	(2.1)
Amortization of defined benefit pension and postretirement items, after tax	(1.7)		(1.8)		(5.0)	(5.4)
Reclassifications to earnings	(2.1)		(1.1)		(7.6)	(3.6)
Other expense (income), net | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gains and losses on cash flow hedges, foreign exchange contracts, before tax	$ (0.5)		$ 1.0		$ (3.7)	$ 2.6

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