Restructuring, Reserve (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
2020 Restructuring Program
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance		$ 1.6	$ 1.2
Charge to Income	$ 13.8	1.4
Cash	12.5	2.3
Non-Cash	0.0	0.0
Restructuring Reserve, Ending Balance	2.5	0.7	2.5
2019 Restructuring Program
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance		4.1	8.2
Charge to Income		(0.6)	18.0
Cash		11.8	18.1
Non-Cash		(8.4)	(4.0)
Restructuring Reserve, Ending Balance	4.1	0.1	4.1
Severance & termination related costs | 2020 Restructuring Program
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance		0.9	0.4
Charge to Income	1.0	0.3
Cash	0.5	0.5
Non-Cash	0.0	0.0
Restructuring Reserve, Ending Balance	0.9	0.7	0.9
Severance & termination related costs | 2019 Restructuring Program
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance		1.4	5.3
Charge to Income		(0.1)	(0.1)
Cash		1.2	3.6
Non-Cash		0.0	0.0
Restructuring Reserve, Ending Balance	1.6	0.1	1.6
Accelerated depreciation & asset write-offs | 2019 Restructuring Program
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance		0.0	0.0
Charge to Income		1.2	4.0
Cash		0.0	0.0
Non-Cash		(1.2)	(4.0)
Restructuring Reserve, Ending Balance	0.0	0.0	0.0
Other exit costs | 2020 Restructuring Program
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance		0.7	0.8
Charge to Income	12.8	1.1
Cash	12.0	1.8
Non-Cash	0.0	0.0
Restructuring Reserve, Ending Balance	1.6	0.0	1.6
Other exit costs | 2019 Restructuring Program
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance		2.2	2.9
Charge to Income		2.8	14.1
Cash		5.0	14.5
Non-Cash		0.0	0.0
Restructuring Reserve, Ending Balance	$ 2.5	0.0	$ 2.5
Net gain on sale of fixed assets | 2019 Restructuring Program
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance		0.5
Charge to Income		0.0
Cash		0.5
Non-Cash		0.0
Restructuring Reserve, Ending Balance		0.0
Gain on termination of capital lease | 2019 Restructuring Program
Restructuring Reserve [Roll Forward]
Restructuring Reserve, Beginning Balance		0.0
Charge to Income		(4.5)
Cash		5.1
Non-Cash		(9.6)
Restructuring Reserve, Ending Balance		$ 0.0