| In millions, except per share items | Aug-31-23 | May-31-23 | Aug-31-22 | May-31-22 | Feb-28-22 | Nov-30-21 | Aug-31-21 | May-31-21 |
| | 10-Q | 10-Q | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q |
| Sales | | | 1,070.2 | 795.0 | 817.7 | 788.6 | 783.5 | 855.5 |
| Sales growth | | | 36.6% | -7.1% | -2.5% | -11.3% | -17.8% | |
| Costs and Expenses | | | | | | | | |
| Cost of sales | | | 796.4 | 586.3 | 611.1 | 591.5 | 588.7 | 651.0 |
| Gross margin | | | 273.8 | 208.7 | 206.6 | 197.1 | 194.8 | 204.5 |
| Gross margin | | | 25.6% | 26.3% | 25.3% | 25.0% | 24.9% | 23.9% |
| Selling, general and administrative | | | 127.4 | 106.5 | 101.6 | 97.8 | 96.2 | 106.5 |
| Operating income from continuing operations | | | 148.2 | 104.0 | 106.8 | 99.5 | 97.3 | 78.0 |
| Operating margin | | | 13.8% | 13.1% | 13.1% | 12.6% | 12.4% | 9.1% |
| Interest expense | | | -38.6 | -12.1 | -6.4 | -7.3 | -8.0 | -8.7 |
| Other (income) expense, net | | | 0.7 | 0.7 | -0.3 | 0.6 | -1.5 | -1.5 |
| Income from continuing operations before income taxes | | | 56.4 | 38.7 | | | 18.2 | |
| Income tax expense | | | 25.7 | 18.8 | 21.4 | 17.7 | 18.4 | 14.3 |
| Net income from continuing operations | | | 40.5 | 29.6 | | | 14.3 | |
| Income from discontinued operations, net of tax | | | 15.5 | 13.4 | | | 4.7 | |
| Loss on disposal of discontinued operations, net of tax | | | -80.7 | 8.7 | | | | |
| Net income (loss) from discontinued operations | | | -74.0 | 13.4 | | | 4.7 | |
| Net income (loss) | | | 9.2 | 85.8 | 84.0 | 78.6 | 77.2 | 56.4 |
| Dividends on preferred stock | | | -1.0 | | | | | |
| Net income (loss) available to common shareholders | | | -34.5 | 43.1 | | | 19.0 | |
| |
| Basic earnings (loss) per share | | | | | | | | |
| Earnings | | | 0.0 | 0.0 | | | 0.0 | |
| Earnings | | | 0.0 | 0.0 | | | 0.0 | |
| |
| Basic earnings per common share (usd per share) | | | $0.33 | $3.45 | $3.37 | $3.13 | $3.04 | $2.21 |
| |
| Diluted Earnings (Loss) Per Share [Abstract] | | | | | | | | |
| Diluted earnings per common share (usd per share) | | | $0.77 | $3.44 | $3.36 | $3.11 | $3.02 | $2.19 |
| Earnings | | | 0.0 | 0.0 | | | 0.0 | |
| Earnings | | | 0.0 | 0.0 | | | 0.0 | |
| |
| Weighted average shares outstanding | | | | | | | | |
| Weighted average number common shares, basic (shares) | | | 24.8 | 18.6 | 18.7 | 18.9 | 19.2 | 25.8 |
| Weighted average number common shares, diluted (shares) | | | 26.2 | 18.9 | 18.8 | 19.1 | 19.3 | 25.9 |
| |
| Cash dividends declared per common share (usd per share) | | | $0.68 | $0.68 | $0.68 | $0.68 | $0.68 | $0.68 |