Restructuring And Related Charges (Rollforward Of Restructuring Accrual) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Restructuring Cost and Reserve [Line Items]
Accrual balance at beginning	$ 7.8	$ 15.7
Provisions	34.6	9.1
Cash expenditures	(7.1)	(17.0)
Non-cash items	(1.7)
Accrual balance at ending	33.6	7.8
Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Accrual balance at beginning	3.1	6.6
Provisions	7.9	4.9
Cash expenditures	(3.8)	(8.4)
Non-cash items	(0.6)
Accrual balance at ending	6.6	3.1
Other Costs [Member]
Restructuring Cost and Reserve [Line Items]
Accrual balance at beginning	4.7	9.1
Provisions	26.7	4.2
Cash expenditures	(3.3)	(8.6)
Non-cash items	(1.1)
Accrual balance at ending	$ 27.0	$ 4.7