Restructuring Charges (Schedule of Restructuring Activities and Related Accruals) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Restructuring Reserve [Roll Forward]
Restructuring reserve	$ 2.5	$ 5.5
Restructuring charges, charge to income	17.1	16.2
Utilized - cash payments	(14.2)	(18.4)
Utilized - non cash	(0.8)	(0.8)
Restructuring reserve	4.6	2.5
Severance and related benefit costs
Restructuring Reserve [Roll Forward]
Restructuring reserve	1.7	1.9
Restructuring charges, charge to income	6.2	5.6
Utilized - cash payments	(4.0)	(5.8)
Utilized - non cash	0.0	0.0
Restructuring reserve	3.9	1.7
Asset impairment and accelerated depreciation
Restructuring Reserve [Roll Forward]
Restructuring reserve	0.0	0.0
Restructuring charges, charge to income	0.8	0.8
Utilized - cash payments	0.0	0.0
Utilized - non cash	(0.8)	(0.8)
Restructuring reserve	0.0	0.0
Other exit costs
Restructuring Reserve [Roll Forward]
Restructuring reserve	0.8	3.6
Restructuring charges, charge to income	10.1	9.8
Utilized - cash payments	(10.2)	(12.6)
Utilized - non cash	0.0	0.0
Restructuring reserve	$ 0.7	$ 0.8