Retirement Plans (Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan, Service Cost	$ 0.4	$ 0.4
Defined Benefit Plan, Interest Cost	2.5	2.8
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(3.9)	(4.2)
Amortization of actuarial net loss	0.6	0.7
Defined Benefit Plan, Net Periodic Benefit Cost other than Service Cost	(0.8)	(0.7)
Net periodic benefit cost	$ (0.4)	$ (0.3)