Taxes - Schedule of unrecognized tax benefits (Details) - USD ($) $ in Millions |
12 Months Ended | ||
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May 31, 2026 |
May 31, 2025 |
May 31, 2024 |
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| Unrecognized Tax Benefits [Roll Forward] | |||
| Gross unrecognized benefits, Beginning of period | $ 1.2 | $ 1.8 | $ 2.0 |
| Decreases related to prior year tax positions | 0.0 | 0.0 | (0.8) |
| Increase related to prior year tax positions | 1.9 | 0.1 | 0.7 |
| Increases related to current year tax positions | 0.1 | 0.1 | 0.1 |
| Settlements during the period | 0.0 | 0.0 | (0.2) |
| Lapse of statute of limitation | (0.6) | (0.8) | 0.0 |
| Gross unrecognized benefits, End of period | $ 2.6 | $ 1.2 | $ 1.8 |
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
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- Definition Amount of unrecognized tax benefits. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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