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Summary of Significant Accounting Policies - Amounts Reclassified out of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Aug. 31, 2024 | Aug. 31, 2023 | Aug. 31, 2022
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items] |  |  |
Interest and foreign exchange | $ 100.8 | $ 85.4 | $ 57.4
Total before tax | (223.7) | (91.0) | (60.6)
Tax expense (benefit) | 62.0 | 24.6 | 18.1
Unrealized (Gain) Loss on Derivative Financial Instruments | Reclassification out of Accumulated Other Comprehensive loss |  |  |
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items] |  |  |
Total before tax | (18.7) | (12.8) | 6.1
Tax expense (benefit) | 4.0 | 3.7 | (1.4)
Net of tax | (14.7) | (9.1) | 4.7
Unrealized (Gain) Loss on Derivative Financial Instruments | Reclassification out of Accumulated Other Comprehensive loss | Foreign Exchange Contracts |  |  |
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items] |  |  |
Revenue and Cost of revenue | (2.0) | (2.0) | 1.2
Unrealized (Gain) Loss on Derivative Financial Instruments | Reclassification out of Accumulated Other Comprehensive loss | Interest rate swap contracts |  |  |
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items] |  |  |
Interest and foreign exchange | $ (16.7) | $ (10.8) | $ 4.9

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