RELATED-PARTY TRANSACTIONS - Summary of Charges and Credits (Details) - CHF (SFr) SFr in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Credits (charges) included in: | |||
| Revenue | SFr 0.3 | SFr 0.3 | SFr 0.3 |
| Direct costs | (1.6) | (2.4) | (1.1) |
| Personnel expenses | 0.0 | 0.0 | 0.0 |
| Included in operating (loss) | (1.3) | (2.1) | (0.8) |
| Finance expense | 0.0 | 0.0 | 0.0 |
| Finance income | 0.0 | 0.0 | 0.0 |
| Included in net (loss) | (1.3) | (2.1) | (0.8) |
| Property and equipment transfers in, net | 0.0 | 0.0 | 0.0 |
| LG | |||
| Credits (charges) included in: | |||
| Revenue | 0.0 | 2.8 | 4.3 |
| Direct costs | 0.0 | (1.3) | (1.2) |
| Personnel expenses | 0.0 | (15.9) | (18.6) |
| Other operating expenses | 0.0 | (116.9) | (118.1) |
| Included in operating (loss) | 0.0 | (131.3) | (133.6) |
| Finance expense | 0.0 | (1.5) | (1.7) |
| Finance income | 0.0 | 3.0 | 2.1 |
| Included in net (loss) | 0.0 | (129.8) | (133.2) |
| Property and equipment transfers in, net | SFr 0.0 | SFr 11.3 | SFr 23.7 |