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Income Taxes (Narrative) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2021
Unrecognized Tax Benefits, Interest on Income Taxes Accrued | $ 0.8 | $ 0.7 |
Income tax expense (benefit) | 23.5 | 22.0 | $ 24.5
Deferred Tax Assets, Tax Credit Carryforwards, Foreign |  | 4.7 |
Unrecognized Tax Benefits | 5.0 | 4.7 | $ 4.8
Unrecognized Tax Benefits, Decrease Resulting from Current Period Tax Positions | 0.0 | 0.4 |
Unrecognized Tax Benefits, Decrease Resulting from Foreign Currency Translation | (0.1) | $ 0.1 |
transition tax liability | $ 4.1 |  |

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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible foreign tax credit carryforwards. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-6 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-8 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482685/740-10-50-3 + Details
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