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Retirement Plans (Tables) | 12 Months Ended
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Sep. 30, 2023
Retirement Benefits [Abstract] |
Schedule of Net Periodic Benefit Cost | The components of net periodic cost (benefit) for our Pension Plan are presented below.
| 2023 |  | 2022 |  | 2021 |  |  |  |
| (in millions)
Service cost | $ | 0.8 |  |  | $ | 1.3 |  |  | $ | 1.5 |  |  |  |  |
Components of net periodic cost (benefit) excluded from operating income: |  |  |  |  |  |  |  |  |
Interest cost | 13.9 |  |  | 9.8 |  |  | 9.9 |  |  |  |  |
Expected return on plan assets | (13.9) |  |  | (15.4) |  |  | (15.7) |  |  |  |  |
Amortization of actuarial net loss | 3.7 |  |  | 1.7 |  |  | 2.5 |  |  |  |  |
Pension expense (benefit) other than service | 3.7 |  |  | (3.9) |  |  | (3.3) |  |  |  |  |
Net periodic cost (benefit) | $ | 4.5 |  |  | $ | (2.6) |  |  | $ | (1.8) |  |  |  |  |
Schedule of Accumulated and Projected Benefit Obligations | P
Schedule Of Defined Benefit Plans Disclosures | Amounts recognized for the Pension Plan are presented below.
| September 30,
| 2023 |  | 2022
| (in millions)
Projected benefit obligations: |  |  |
Beginning of year | $ | 251.2 |  |  | $ | 336.8 |
Service cost | 0.8 |  |  | 1.3 |
Interest cost | 13.9 |  |  | 9.8 |
Actuarial gain | (10.4) |  |  | (74.0) |
Benefits paid | (22.3) |  |  | (22.7) |
Accumulated benefit obligations at end of year | $ | 233.2 |  |  | $ | 251.2 |
Plan assets: |  |  |
Beginning of year | $ | 251.8 |  |  | $ | 353.5 |
Actual return on plan assets | 10.3 |  |  | (79.0) |
Benefits paid | (22.3) |  |  | (22.7) |
Fair value of plan assets at end of year | $ | 239.8 |  |  | $ | 251.8 |
Accrued benefit cost at end of year: |  |  |
Funded status | $ | 6.6 |  |  | $ | 0.6 |
Recognized on balance sheet: |  |  |
Other noncurrent assets | $ | 6.6 |  |  | $ | 0.6 |
Recognized in accumulated other comprehensive income (loss), before tax: |  |  |
Net actuarial loss | $ | 68.2 |  |  | $ | 78.7 |
| $ | 68.2 |  |  | $ | 78.7 |
Schedule of Pension and Other Postretirement Benefits Activity in Accumulated Other Comprehensive Income (Loss) [Table Text Block] | Pension Plan activity in accumulated other comprehensive loss, before tax, in 2023 is presented below, in millions.
Balance at beginning of year | $ | 78.7 |
Actuarial loss | (6.8) |
Prior year actuarial loss amortization to net periodic cost | (3.7) |
Balance at end of year | $ | 68.2 |
Schedule of Assumptions Used | A summary of key assumptions for the valuations of our Pension Plan is as follows:
| September 30,
| 2023 |  | 2022 |  | 2021
Weighted average used to determine benefit obligations: |  |  |  |  |
Discount rate | 6.29 | % |  | 5.79 | % |  | 3.01 | %
Weighted average used to determine net periodic cost: |  |  |  |  |
Discount rate | 5.79 | % |  | 3.01 | % |  | 2.84 | %
Expected return on plan assets | 5.75 | % |  | 4.50 | % |  | 4.50 | %
Schedule of Strategic Allocation of Plan Assets [Table Text Block] | Strategic asset allocations, tactical range at September 30, 2023 and actual asset allocations are as follows:
| Strategic asset allocation |  |  |  |  |  | Actual asset allocations at
|  |  |  |  |  | September 30,
|  | Tactical range |  | 2023 |  | 2022 |  | 2021
Fixed income investments | 70 | % |  | 67 | % | - | 73 | % |  | 70 | % |  | 70 | % |  | 70 | %
Equity investments | 30 |  |  | 27 | % | - | 33 | % |  | 29 |  |  | 29 |  |  | 29 |
Cash | — |  |  | 0 | % | - | 5 | % |  | 1 |  |  | 1 |  |  | 1 |
| 100 | % |  |  |  |  |  | 100 | % |  | 100 | % |  | 100 | %
Schedule of Allocation of Plan Assets | The assets of the Pension Plan by level within the fair value hierarchy are as follows:
| September 30, 2023
| Level 1 |  | Level 2 |  |  |  | Total
| (in millions)
Fixed income | $ | 121.1 |  |  | $ | 45.6 |  |  |  |  | $ | 166.7 |
Equity: |  |  |  |  |  |  |
Large cap index funds | 35.6 |  |  | — |  |  |  |  | 35.6 |
International stocks: |  |  |  |  |  |  |
International funds | 35.6 |  |  | — |  |  |  |  | 35.6 |
Total equity | 71.2 |  |  | — |  |  |  |  | 71.2 |
Cash and cash equivalents | 1.9 |  |  | — |  |  |  |  | 1.9 |
Total Plan assets | $ | 194.2 |  |  | $ | 45.6 |  |  |  |  | $ | 239.8 |
| September 30, 2022
| Level 1 |  | Level 2 |  |  |  | Total
| (in millions)
Fixed income | $ | 125.2 |  |  | $ | 50.1 |  |  |  |  | $ | 175.3 |
Equity: |  |  |  |  |  |  |
Large cap index funds | 37.2 |  |  | — |  |  |  |  | 37.2 |
International stocks: |  |  |  |  |  |  |
International funds | 37.4 |  |  | — |  |  |  |  | 37.4 |
Total equity | 74.6 |  |  | — |  |  |  |  | 74.6 |
Cash and cash equivalents | 1.9 |  |  | — |  |  |  |  | 1.9 |
Total Plan assets | $ | 201.7 |  |  | $ | 50.1 |  |  |  |  | $ | 251.8 |
Schedule of Expected Benefit Payments | Our estimated future pension benefit payments are presented below (in millions):
2024 | $ | 23.0 |
2025 | 22.7 |
2026 | 22.3 |
2027 | 21.9 |
2028 | 21.4 |
2029-2033 | 97.3 |
Total | $ | 208.6 |

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