| CHF million | 
 | Reporting half-year ended 31.12.2024 | % | 
 | Financial year ended 30.06.2024 | % | 
 | Reporting half-year ended 31.12.2023 | % | 
| Current assets | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
| Cash and cash equivalents | 
 | 135.9 | 7.1 | 
 | 150.4 | 7.7 | 
 | 114.4 | 6.2 | 
| Trade receivables | 
 | 433.8 | 22.6 | 
 | 483.1 | 24.5 | 
 | 425.8 | 23.0 | 
| Inventories | 
 | 529.1 | 27.6 | 
 | 497.0 | 25.3 | 
 | 488.1 | 26.3 | 
| Current income tax assets | 
 | 20.0 | 1.0 | 
 | 17.8 | 0.9 | 
 | 13.6 | 0.7 | 
| Other current assets | 
 | 71.0 | 3.7 | 
 | 67.9 | 3.5 | 
 | 75.9 | 4.1 | 
| Total current assets | 
 | 1,189.8 | 62.0 | 
 | 1,216.2 | 61.9 | 
 | 1,117.8 | 60.3 | 
| Non-current assets | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
| Property, plant, and equipment | 
 | 401.0 | 20.9 | 
 | 403.5 | 20.5 | 
 | 380.3 | 20.5 | 
| Intangible assets | 
 | 148.5 | 7.7 | 
 | 164.5 | 8.4 | 
 | 175.8 | 9.5 | 
| Non-current financial assets | 
 | 42.4 | 2.2 | 
 | 44.2 | 2.2 | 
 | 41.0 | 2.2 | 
| Deferred income tax assets | 
 | 137.4 | 7.2 | 
 | 137.1 | 7.0 | 
 | 139.5 | 7.5 | 
| Total non-current assets | 
 | 729.3 | 38.0 | 
 | 749.3 | 38.1 | 
 | 736.6 | 39.7 | 
| Total assets | 
 | 1,919.1 | 100.0 | 
 | 1,965.5 | 100.0 | 
 | 1,854.4 | 100.0 | 
| CHF million | 
 | Reporting half-year ended 31.12.2024 | % | 
 | Financial year ended 30.06.2024 | % | 
 | Reporting half-year ended 31.12.2023 | % | 
| Current liabilities | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
| Current borrowings | 
 | 323.7 | 16.9 | 
 | 6.2 | 0.3 | 
 | 101.7 | 5.5 | 
| Trade payables | 
 | 167.2 | 8.7 | 
 | 180.2 | 9.2 | 
 | 162.0 | 8.7 | 
| Current income tax liabilities | 
 | 36.5 | 1.9 | 
 | 36.9 | 1.9 | 
 | 38.9 | 2.1 | 
| Accrued and other current liabilities | 
 | 370.5 | 19.3 | 
 | 419.4 | 21.3 | 
 | 349.9 | 18.9 | 
| Provisions | 
 | 86.0 | 4.4 | 
 | 86.8 | 4.4 | 
 | 39.4 | 2.1 | 
| Total current liabilities | 
 | 983.9 | 51.2 | 
 | 729.5 | 37.1 | 
 | 691.9 | 37.3 | 
| Non-current liabilities | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
| Accrued pension and other employee benefits | 
 | 251.0 | 13.1 | 
 | 253.2 | 12.9 | 
 | 244.8 | 13.2 | 
| Deferred income tax liabilities | 
 | 23.2 | 1.2 | 
 | 21.9 | 1.1 | 
 | 31.7 | 1.7 | 
| Non-current provisions | 
 | 12.5 | 0.7 | 
 | 19.5 | 1.0 | 
 | 0.0 | 0.0 | 
| Non-current liabilities | 
 | 278.6 | 14.5 | 
 | 599.0 | 30.5 | 
 | 599.2 | 32.3 | 
| Total non-current liabilities | 
 | 565.3 | 29.5 | 
 | 893.6 | 45.5 | 
 | 875.7 | 47.2 | 
| Total liabilities | 
 | 1,549.2 | 80.7 | 
 | 1,623.1 | 82.6 | 
 | 1,567.6 | 84.5 | 
| Equity | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
| Share capital | 
 | 0.4 | 0.0 | 
 | 0.4 | 0.0 | 
 | 0.4 | 0.0 | 
| Additional paid-in capital | 
 | 811.3 | 42.3 | 
 | 811.3 | 41.3 | 
 | 811.3 | 43.8 | 
| Retained earnings | 
 | –464.2 | –24.2 | 
 | –481.0 | –24.5 | 
 | –499.3 | –26.9 | 
| Treasury shares | 
 | –5.6 | –0.3 | 
 | –5.7 | –0.3 | 
 | –6.9 | –0.4 | 
| Translation exchange differences | 
 | –70.7 | –3.7 | 
 | –69.3 | –3.5 | 
 | –79.2 | –4.3 | 
| Total equity owners of the parent | 
 | 271.2 | 14.1 | 
 | 255.7 | 13.0 | 
 | 226.3 | 12.2 | 
| Minority interests | 
 | 98.7 | 5.2 | 
 | 86.7 | 4.4 | 
 | 60.5 | 3.3 | 
| Total equity | 
 | 369.9 | 19.3 | 
 | 342.4 | 17.4 | 
 | 286.8 | 15.5 | 
| Total liabilities and equity | 
 | 1,919.1 | 100.0 | 
 | 1,965.5 | 100.0 | 
 | 1,854.4 | 100.0 |