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Derivative Financial Instruments and Fair Value Measurements | 3 Months Ended
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Dec. 31, 2025
Derivative Financial Instruments and Fair Value Measurements [Abstract] |
Derivative Financial Instruments and Fair Value Measurements | Derivative Financial Instruments and Fair Value Measurements The Company uses interest rate derivative contracts to hedge interest rate exposures on the Company’s variable rate debt. The Company enters into foreign currency derivative contracts with financial institutions to reduce the risk that its cash flows and earnings will be adversely affected by foreign currency exchange rate fluctuations. The Company’s hedging program is not designated for trading or speculative purposes. The Company recognizes derivative instruments as either assets or liabilities on the accompanying consolidated balance sheets at fair value. The Company records changes in the fair value (i.e., gains or losses) of the derivatives that have been designated as accounting hedges in the accompanying consolidated statements of operations as cost of revenue, interest expense or to accumulated other comprehensive loss in the accompanying consolidated balance sheets. Cash Flow Hedges The Company uses interest rate swap and interest rate cap agreements designated as cash flow hedges to limit exposure to variable interest rates on portions of the Company’s debt. The Company initially reports any gain on the effective portion of a cash flow hedge as a component of accumulated other comprehensive loss. Depending on the type of cash flow hedge, the gain is subsequently reclassified against interest expense when the interest expense on the variable rate debt is recognized. If the hedged transaction becomes probable of not occurring, any gain or loss related to interest rate swap or interest rate cap agreements would be recognized in other income. The notional principal, fixed rates and related effective and expiration dates of the Company’s outstanding interest rate swap agreements were as follows:
December 31, 2025
Notional Amount Currency |  | Notional Amount (in millions) |  | Fixed Rate |  | Effective Date |  | Expiration Date
USD |  | 400.0 |  | 1.283% |  | February 2023 |  | March 2028
September 30, 2025
Notional Amount Currency |  | Notional Amount (in millions) |  | Fixed Rate |  | Effective Date |  | Expiration Date
USD |  | 400.0 |  | 1.283% |  | February 2023 |  | March 2028
In the fourth quarter of fiscal 2021, the Company entered into interest rate swap agreements with a notional value of $400.0 million to manage the interest rate exposure of its variable rate loans. The swaps became effective February 2023 and terminate in March 2028. By entering into the swap agreements, the Company converted a portion of the SOFR rate-based liability into a fixed rate liability. The Company pays a fixed rate of 1.283% and receives payment at the prevailing one-month SOFR. In the third quarter of fiscal 2022, the Company purchased interest rate cap agreements with a notional value of $300.0 million to manage interest rate exposure of its variable rate loans. The caps became effective on June 30, 2022 and terminate in March 2028. The caps reduce the Company’s exposure to one-month SOFR. In the event one-month SOFR exceeds 3.465%, the Company will receive the spread between prevailing one-month SOFR and 3.465%. See Note 14 for accumulated balances and reporting period activities of derivatives related to reclassifications out of accumulated other comprehensive loss for the three months ended December 31, 2025 and 2024. Additionally, there were no material losses recognized in income due to amounts excluded from effectiveness testing from the Company’s interest rate swap agreements. Other Foreign Currency Forward Contracts The Company uses foreign currency forward contracts which are not designated as accounting hedges to hedge intercompany transactions and other monetary assets or liabilities denominated in currencies other than the functional currency of a subsidiary. Gains and losses on these contracts were not material for the three months ended December 31, 2025 and 2024. Fair Value Measurements The fair values of the interest rate swap and interest rate cap agreements were derived by taking the net present value of the expected cash flows using observable market inputs (Level 2) such as SOFR rate curves, futures, volatilities and basis spreads (when applicable). As discussed in Note 3, the Company received an equity investment in the civil infrastructure construction business buyer and concurrently participated as a member of a lending group in a revolving credit facility. The Company elected the fair value option for its equity investment due to the availability of quoted prices of identical assets. The fair value option was also elected for the credit facility investment. Changes in fair value of both investments are classified within other income on the consolidated statements of operations. The Company records interest income at the stated coupon rate of the credit facility and classifies it within interest income on the consolidated statement of operations. Fair value for the equity investment is determined using Level 1 inputs, and fair value of the credit facility investment is determined using Level 3 inputs, such as estimated cash flows and estimated discount rates. The Company recorded a gain of $1.0 million and $5.0 million in other income in the first three months of fiscal 2026 and 2025, respectively, representing the increase in fair value of these investments. In the fourth quarter of fiscal 2025, the Company issued contingent consideration in connection with the acquisition of a business, with a maximum value of $17.7 million. The contingent consideration is a liability that is measured at fair value with changes in fair value reported in other income. The contingent consideration is measured using Level 2 inputs, such as quoted market prices and volatilities. The Company recorded a gain of $4.1 million in other income in the first three months of fiscal 2026. Below are the Company's non-pension financial assets and liabilities recorded at fair value on a recurring basis within the ASC 820-10 fair value hierarchy:
| December 31, 2025
| Balance Sheet Location |  | Quoted Prices in Active Markets for Identical Assets (Level 1) |  | Significant Observable Inputs (Level 2) |  | Significant Unobservable Inputs (Level 3) |  | Total Fair Value
Interest rate contracts | Other current assets |  | $ | — |  |  | $ | 8.3 |  |  | $ | — |  |  | $ | 8.3 |
Interest rate contracts | Other non-current assets |  | — |  |  | 8.8 |  |  | — |  |  | 8.8 |
Interest rate contracts | Other current liabilities |  | — |  |  | (2.2) |  |  | — |  |  | (2.2) |
Interest rate contracts | Other long-term liabilities |  | — |  |  | (2.3) |  |  | — |  |  | (2.3) |
Credit facility investment | Other non-current assets |  | — |  |  | — |  |  | 23.0 |  |  | 23.0 |
Contingent Consideration | Other long-term liabilities |  | — |  |  | (3.4) |  |  | — |  |  | (3.4) |
Equity investment | Other non-current assets |  | 23.6 |  |  | — |  |  | — |  |  | 23.6 |
Total net assets at fair value |  | $ | 23.6 |  |  | $ | 9.2 |  |  | $ | 23.0 |  |  | $ | 55.8 |
| September 30, 2025
| Balance Sheet Location |  | Quoted Prices in Active Markets for Identical Assets (Level 1) |  | Significant Observable Inputs (Level 2) |  | Significant Unobservable Inputs (Level 3) |  | Total Fair Value
Interest rate contracts | Other current assets |  | $ | — |  |  | $ | 9.0 |  |  | $ | — |  |  | $ | 9.0 |
Interest rate contracts | Other non-current assets |  | — |  |  | 10.0 |  |  | — |  |  | 10.0 |
Interest rate contracts | Other current liabilities |  | — |  |  | (1.8) |  |  | — |  |  | (1.8) |
Interest rate contracts | Other long-term liabilities |  | — |  |  | (2.8) |  |  | — |  |  | (2.8) |
Credit facility investment | Other non-current assets |  | — |  |  | — |  |  | 17.4 |  |  | 17.4 |
Contingent Consideration | Other long-term liabilities |  | — |  |  | (7.5) |  |  | — |  |  | (7.5) |
Equity investment | Other non-current assets |  | 21.9 |  |  | — |  |  | — |  |  | 21.9 |
Total net assets at fair value |  | $ | 21.9 |  |  | $ | 6.9 |  |  | $ | 17.4 |  |  | $ | 46.2 |
The table below sets forth a summary of changes in the fair value of the Company's Level 3 investment assets:
|  | Three Months Ended December 31, 2025
|  | Beginning Balance |  | Investment Gains/(Losses) |  | Interest Earned |  | Loans |  | Collections |  | Ending Balance
Credit facility investment including accrued interest | $ | 17.4 |  |  | (0.8) |  |  | 0.4 |  |  | 6.0 |  |  |  |  | $ | 23.0 |

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