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Related Party Transactions - Additional Information (Detail) - Axis LLC - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Feb. 29, 2024 | Feb. 28, 2023 | Feb. 29, 2024 | Feb. 28, 2023
Related Party Transaction [Line Items] |  |  |  |
Percentage of ownership in entity | 41.90% |  | 41.90% |
Railcar Components |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Purchases of goods from related party | $ 2.5 | $ 1.8 | $ 4.8 | $ 4.5

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