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v3.23.3

Borrowing Arrangements (Narrative) (Details) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2023 | Sep. 30, 2021 | Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2021
Debt Instrument [Line Items] |  |  |  |  |
Long-term Debt, Gross | $ 451.3 |  | $ 451.3 | $ 451.6 |
Outstanding Letter Of Credit Accrued Fees And Expenses | 0.2 |  | 0.2 |  |
Long-Term Debt, Maturity, Year One | 0.7 |  | 0.7 |  |
Long-Term Debt, Maturity, Year Two | 0.4 |  | 0.4 |  |
Long-Term Debt, Maturity, Year Three | 0.2 |  | 0.2 |  |
Long-Term Debt, Maturity, Year Four and Five | 0.0 |  | 0.0 |  |
CY plus 6 and more | 450.0 |  | 450.0 |  |
Outstanding Letter of Credit | 12.4 |  | 12.4 |  |
Gain (Loss) on Extinguishment of Debt |  |  | 0.0 | 0.0 | $ (16.7)
Payment for Debt Extinguishment or Debt Prepayment Cost |  |  |  | 12.4 |
Write off of Deferred Debt Issuance Cost |  |  |  | $ 4.3 |
Revolving Credit Facility [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity | 175.0 |  | 175.0 |  |
Maximum excess availability level at which financial maintenance covenants would apply |  |  | 17.5 |  |
Line of Credit Facility, Remaining Borrowing Capacity | $ 162.4 |  | $ 162.4 |  |
Bonds [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Interest Rate, Effective Percentage | 4.00% | 5.50% | 4.00% |  | 5.50%
Unsecured Debt [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Long-term Debt, Gross | $ 450.0 |  | $ 450.0 |  |
Payments of Debt Issuance Costs |  | $ 5.5 |  |  |
Unsecured Debt [Member] | 5.5% Senior Notes |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Unsecured Debt |  | $ 450.0 |  |  | $ 450.0
Swing Line Loans [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity | 25.0 |  | 25.0 |  |
Letter Of Credit [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity | $ 60.0 |  | 60.0 |  |
Domestic Line of Credit |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Potential Increase In The Size Of Credit Facility |  |  | $ 150.0 |  |
Line of Credit Facility, Borrowing Base, Percentage of Eligible Accounts Receivable | 85.00% |  | 85.00% |  |
Line of Credit Facility, Borrowing Base, Percentage of Eligible Inventory | 70.00% |  | 70.00% |  |
Line of Credit Facility, Borrowing Base, Percentage of Net Orderly Liquidation Value of Eligible Inventory | 85.00% |  | 85.00% |  |
Line of Credit Facility, Covenant, Percent of Loan Cap | 10.00% |  | 10.00% |  |
5.5% Senior Notes |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Financial Liabilities Fair Value Disclosure | $ 393.7 |  | $ 393.7 |  |
Minimum [Member] | Domestic Line of Credit |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage |  |  | 3750.00% |  |
Base Rate [Member] | Domestic Line of Credit |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Line of Credit Facility, Interest Rate at Period End | 10000.00% |  | 10000.00% |  |
Base Rate [Member] | Minimum [Member] | Revolving Credit Facility [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  | 100.00% |  |
Base Rate [Member] | Maximum [Member] | Revolving Credit Facility [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  | 125.00% |  |
Secured Overnight Financing Rate | Domestic Line of Credit |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate | 1000.00% |  |  |  |
Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate | Domestic Line of Credit |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Line of Credit Facility, Interest Rate at Period End | 200.00% |  | 200.00% |  |
Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate | Minimum [Member] | Domestic Line of Credit |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  | 200.00% |  |
Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate | Maximum [Member] | Domestic Line of Credit |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  | 225.00% |  |

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