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Retirement Plans (Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Defined Benefit Plan, Service Cost	$ 0.4	$ 0.4	$ 0.8	$ 0.8
Defined Benefit Plan, Interest Cost	2.8	3.5	5.6	7.0
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	(4.2)	(4.0)	(8.4)	(8.1)
Amortization of actuarial net loss	0.6	0.5	1.3	1.0
Curtailment/special settlement loss (gain)	0.0	1.0	0.0	1.0
Defined Benefit Plan, Net Periodic Benefit Cost other than Service Cost	(0.8)	1.0	(1.5)	0.9
Net periodic benefit cost	$ (0.4)	$ 1.4	$ (0.7)	$ 1.7

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- Definition

Defined Benefit Plan, Net Periodic Benefit Cost other than Service Cost

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- Definition

Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan.

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Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan.

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Amount of cost recognized for passage of time related to defined benefit plan.

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Amount of gain (loss) recognized in net periodic benefit (cost) credit from event reducing expected years of future service of present employees or eliminating accrual of defined benefits for some or all future services of present employees.

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