| CHF million | 
 | Reporting half-year ended 31.12.2024 | 
 | Reporting half-year ended 31.12.2023 | 
| Net profit | 
 | 96.7 | 
 | 48.5 | 
| Depreciation and amortization | 
 | 50.9 | 
 | 66.1 | 
| Income tax expenses | 
 | 34.0 | 
 | 27.7 | 
| Interest expenses | 
 | 16.8 | 
 | 19.4 | 
| Interest income | 
 | –1.3 | 
 | –1.1 | 
| (Gain) Loss on disposal of fixed assets, net | 
 | –7.3 | 
 | –4.4 | 
| Adjustment for other non-cash and non-operational items | 
 | 4.6 | 
 | –8.7 | 
| Change in trade receivables | 
 | 37.9 | 
 | 13.2 | 
| Change in inventories | 
 | –43.7 | 
 | –25.0 | 
| Change in other current assets | 
 | –3.3 | 
 | –3.7 | 
| Change in trade payables | 
 | –9.9 | 
 | 5.9 | 
| Change in accrued pension and other employee benefits | 
 | 3.4 | 
 | 1.9 | 
| Change in provisions, accrued and other current liabilities | 
 | –40.8 | 
 | 6.2 | 
| Cash generated from operations | 
 | 138.0 | 
 | 146.0 | 
| Income taxes paid | 
 | –35.4 | 
 | –31.2 | 
| Interest paid | 
 | –23.5 | 
 | –26.1 | 
| Interest received | 
 | 1.2 | 
 | 1.1 | 
| Net cash from operating activities | 
 | 80.3 | 
 | 89.8 | 
| Cash flows from investing activities | 
 | 
 | 
 | 
 | 
| Additions of property, plant, and equipment | 
 | –31.5 | 
 | –27.7 | 
| Proceeds from sale of property, plant, and equipment | 
 | 13.9 | 
 | 8.6 | 
| Additions of intangible assets | 
 | –13.4 | 
 | –15.7 | 
| Change in non-current financial assets | 
 | 1.6 | 
 | 0.7 | 
| Acquisition of subsidiaries, net of cash acquired | 
 | 0.0 | 
 | –4.2 | 
| Sale of subsidiaries, net of cash sold | 
 | –0.7 | 
 | 0.2 | 
| Sale of investment in associates and joint ventures | 
 | 0.0 | 
 | 12.1 | 
| Net cash used in investing activities | 
 | –30.1 | 
 | –26.0 | 
| Cash flows from financing activities | 
 | 
 | 
 | 
 | 
| Other proceeds from (repayment of) current borrowings, net | 
 | 0.0 | 
 | –1.8 | 
| Proceeds from (repayment of) non-current borrowings, net | 
 | –2.5 | 
 | –5.4 | 
| Change in other non-current liabilities | 
 | –0.1 | 
 | –0.1 | 
| Dividends paid to company’s shareholders | 
 | –33.5 | 
 | –39.8 | 
| Dividends paid to minority shareholders | 
 | –30.1 | 
 | –33.1 | 
| (Purchase) Sale of treasury shares | 
 | –3.1 | 
 | 0.0 | 
| Net cash flows from financing activities | 
 | –69.3 | 
 | –80.2 | 
| Translation exchange differences | 
 | 4.6 | 
 | 8.7 | 
| Net increase (decrease) in cash and cash equivalents | 
 | –14.5 | 
 | –7.7 | 
| Cash and cash equivalents at beginning of period | 
 | 150.4 | 
 | 122.1 | 
| Cash and cash equivalents at end of period | 
 | 135.9 | 
 | 114.4 | 
| Net increase (decrease) in cash and cash equivalents | 
 | –14.5 | 
 | –7.7 |