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Retirement Plans (Narrative) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2021 | Sep. 30, 2020
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Defined Benefit Plan, Amortization of Gain (Loss) |  | $ (1.7) | $ (2.5) | $ (2.8)
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate |  | 5.79% | 3.01% | 2.84%
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage |  | 100.00% |  |
Discount rate |  | 3.01% | 2.84% | 3.26%
Defined Contribution Plan, Cost |  | $ 7.3 | $ 5.9 | $ 5.3
Minimum [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Defined Benefit Plan Expected Return on Plan Assets Major Asset Classes Time Horizon |  | 1000.00% |  |
Maximum [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Defined Benefit Plan Expected Return on Plan Assets Major Asset Classes Time Horizon |  | 1500.00% |  |
Equity Securities [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage |  | 30.00% |  |
Equity Securities [Member] | Minimum [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage |  | 25.00% |  |
Forecast [Member] |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Defined Benefit Plan, Amortization of Gain (Loss) | $ (3.7) |  |  |

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- Definition Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 45 -Paragraph 3A -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=123453770&loc=SL108413299-114919 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(4) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e1928-114920 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4179-114921 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 18 -URI https://asc.fasb.org/extlink&oid=123450688&loc=d3e4587-114921 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a)(4) -URI https://asc.fasb.org/extlink&oid=123447040&loc=d3e2709-114920 + Details
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