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Business Combinations - Purchase Price Allocation (Details) - USD ($) $ in Thousands | Sep. 30, 2025 | Sep. 26, 2025 | Sep. 30, 2024 | Sep. 30, 2023
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AssetsAcquiredAbstract [Abstract] |  |  |  |
Goodwill | $ 2,443,882 |  | $ 2,312,362 | $ 2,288,678
CalypsoAI |  |  |  |
AssetsAcquiredAbstract [Abstract] |  |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets, Total |  | $ 14,151 |  |
Goodwill |  | 114,156 |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net, Total |  | 145,207 |  |
CalypsoAI | Developed Technology Rights |  |  |  |
AssetsAcquiredAbstract [Abstract] |  |  |  |
Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Finite-Lived |  | $ 16,900 |  |

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