Retirement Benefits (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service costs	$ 0.7	$ 0.4	$ 1.8	$ 1.1
Interest costs	0.2	0.3	0.5	0.9
Expected return on plan assets	(0.3)	(0.1)	(0.6)	(0.4)
Amortization of net loss	0.5	0.3	1.8	0.8
Net periodic pension cost	1.1	0.9	3.5	2.4
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)			0.0	0.0
United States
Defined Benefit Plan Disclosure [Line Items]
Service costs	0.4	0.5	1.1	1.7
Interest costs	2.0	2.4	6.0	7.5
Expected return on plan assets	(3.3)	(3.3)	(9.7)	(9.9)
Amortization of net loss	1.2	0.4	3.6	0.8
Net periodic pension cost	$ 0.3	$ 0.0	1.0	0.2
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)			$ 0.0	$ 0.1