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Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Effective Income Tax Rate Reconciliation, Federal Transition Tax, Amount	$ 0.0	$ 0.0	$ (0.6)
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	0.6	0.4
Income tax expense (benefit)	24.5	22.1	18.3
Deferred Tax Assets, Tax Credit Carryforwards, Foreign		4.5
Unrecognized Tax Benefits	4.8	4.5	$ 3.3
transition tax liability	$ 4.7	$ 5.2

X

- Definition

The dollar amount of Federal Transition Tax associated with the Tax Cuts and Jobs Act.

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transition tax liability

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- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible foreign tax credit carryforwards.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of unrecognized tax benefits.

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Amount of interest expense accrued for an underpayment of income taxes.

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