Retirement Plans (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Retirement Benefits [Abstract]
Service cost	$ 1.0	$ 1.1
Interest cost	2.6	2.5
Expected return on plan assets	(5.3)	(5.6)
Recognized net actuarial loss	1.5	2.3
Net periodic cost	$ (0.2)	$ 0.3