Stock-Based Compensation - Summary of Performance Share Award Activity (Detail) - Performance Award Activity - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands |
12 Months Ended | ||||||
|---|---|---|---|---|---|---|---|
May 31, 2025 |
May 31, 2024 |
May 31, 2023 |
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| Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] | |||||||
| Outstanding, beginning of year | 140,526 | 171,474 | 159,417 | ||||
| Converted to Worthington Steel common shares | [1] | (38,900) | |||||
| Separation related adjustment | 59,232 | ||||||
| Granted | [2] | 75,854 | 116,353 | 117,545 | |||
| Vested | (71,173) | (145,464) | (88,731) | ||||
| Forfeited | (71,427) | (22,169) | (16,757) | ||||
| Outstanding, end of year | 73,780 | 140,526 | 171,474 | ||||
| Weighted Average Grant Date Fair Value | |||||||
| Outstanding, beginning of year | $ 37.55 | $ 46.37 | $ 42.93 | ||||
| Converted to Worthington Steel common shares | [1] | 56.99 | |||||
| Granted | [2] | 41.34 | 52.36 | 43.4 | |||
| Vested | 37.74 | 38.91 | 38.91 | ||||
| Forfeited | 37.66 | 40.18 | 39.36 | ||||
| Outstanding, end of year | $ 41.16 | $ 37.55 | $ 46.37 | ||||
| Weighted Average Remaining Contractual Life (in years) | |||||||
| Weighted average remaining contractual life of outstanding restricted common shares (in years) | 1 year 6 months 3 days | 1 year 5 months 4 days | 1 year 7 months 2 days | ||||
| Aggregate intrinsic value | |||||||
| Aggregate intrinsic value of outstanding restricted common shares | $ 4,346 | $ 8,014 | $ 9,636 | ||||
| Aggregate intrinsic value of restricted common shares vested during the year | $ 3,395 | $ 10,165 | $ 4,056 | ||||
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