Retirement Plans (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2018	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Defined Benefit Plan Disclosure [Line Items]
Payment for Pension and Other Postretirement Benefits				$ 0.7
Defined Benefit Plan, Amortization of Gain (Loss)			$ (2.8)	(1.9)	$ (3.2)
Defined Benefit Plan, Plan Assets, Contributions by Employer			0.1	0.6
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement and Curtailment			0.0	(0.7)	0.0
Payment for Pension Benefits			$ 0.0	$ 0.7	$ 0.0
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate			2.84%	3.26%	4.37%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage			100.00%
Discount rate			3.26%	4.37%	3.88%
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Expected Return on Plan Assets Major Asset Classes Time Horizon			10
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Expected Return on Plan Assets Major Asset Classes Time Horizon			15
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage			20.00%			30.00%
Equity Securities [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage			15.00%
Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Amortization of Gain (Loss)		$ (2.5)
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Payment for Pension and Other Postretirement Benefits	$ 0.4
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement and Curtailment				$ 1.1