Commitments and contingencies - Schedule of Contractual Obligation of Leases (Details) - CHF (SFr) SFr in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Disclosure of maturity analysis for non-derivative financial liabilities [line items] | ||
| Commitments for future lease related obligations | SFr 230.3 | SFr 153.8 |
| Due within 1 year | ||
| Disclosure of maturity analysis for non-derivative financial liabilities [line items] | ||
| Commitments for future lease related obligations | 14.4 | 7.8 |
| Due 1 to 5 years | ||
| Disclosure of maturity analysis for non-derivative financial liabilities [line items] | ||
| Commitments for future lease related obligations | 99.9 | 67.7 |
| Due > 5 years | ||
| Disclosure of maturity analysis for non-derivative financial liabilities [line items] | ||
| Commitments for future lease related obligations | SFr 116.0 | SFr 78.3 |