Restructuring And Related Charges (Rollforward Of Restructuring Accrual) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Restructuring Cost and Reserve [Line Items]
Accrual balance at beginning	$ 17.0	$ 2.3
Provisions	10.8	19.5
Cash expenditures	(18.2)	(4.2)
Non-cash items		(0.6)
Accrual balance at ending	9.6	17.0
Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Accrual balance at beginning	7.1	1.4
Provisions	5.7	9.4
Cash expenditures	(9.0)	(3.2)
Non-cash items		(0.5)
Accrual balance at ending	3.8	7.1
Other Costs [Member]
Restructuring Cost and Reserve [Line Items]
Accrual balance at beginning	9.9	0.9
Provisions	5.1	10.1
Cash expenditures	(9.2)	(1.0)
Non-cash items		(0.1)
Accrual balance at ending	$ 5.8	$ 9.9