| CHF million, except where indicated | 
 | Reporting half-year ended 31.12.2024 | % | 
 | Reporting half-year ended 31.12.2023 | % | 
| Net sales | 
 | 1,421.3 | 
 | 
 | 1,376.5 | 
 | 
| Change in sales | 
 | 44.8 | 3.3 | 
 | –43.3 | –3.0 | 
| translation exchange difference | 
 | –22.3 | –1.6 | 
 | –95.2 | –6.7 | 
| acquisition impact | 
 | 0.0 | 0.0 | 
 | 0.0 | 0.0 | 
| divestment impact | 
 | –1.5 | –0.1 | 
 | 0.0 | 0.0 | 
| organic sales growth | 
 | 68.6 | 5.1 | 
 | 51.9 | 3.9 | 
| Adjusted EBITDA (Adjusted operating profit before depreciation and amortization) | 
 | 216.1 | 15.2 | 
 | 200.7 | 14.6 | 
| Adjusted EBIT (Adjusted operating profit) | 
 | 177.9 | 12.5 | 
 | 165.3 | 12.0 | 
| Profit before taxes | 
 | 130.7 | 9.2 | 
 | 76.2 | 5.5 | 
| Net profit | 
 | 96.7 | 6.8 | 
 | 48.5 | 3.5 | 
| 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
| Other key figures | 
 | 
 | 
 | 
 | 
 | 
 | 
| ROCE (Return on capital employed) 1 | 
 | 29.9% | 
 | 
 | 27.5% | 
 | 
| Net debt | 
 | 466.4 | 
 | 
 | 586.5 | 
 | 
| Market capitalization | 
 | 2,698.5 | 
 | 
 | 1,902.0 | 
 | 
| Average number of full-time equivalent employees | 
 | 15,427 | 
 | 
 | 15,272 | 
 | 
1 The ROCE calculation is based on EBIT, adjusted for items affecting comparability (IAC). The detailed calculation is disclosed in the note on alternative performance measures (APM).