COMMITMENTS AND CONTINGENCIES (Details) - CHF (SFr) SFr in Millions |
3 Months Ended | 12 Months Ended | ||||
|---|---|---|---|---|---|---|
Aug. 25, 2023 |
Sep. 30, 2023 |
Dec. 31, 2024 |
Dec. 31, 2025 |
Nov. 30, 2023 |
Dec. 08, 2017 |
|
| Disclosure of detailed information about commitments and contingencies [Line Items] | ||||||
| Total contractual and purchase commitments | SFr 886.7 | SFr 725.5 | ||||
| Mobile Network Services Claims | ||||||
| Disclosure of detailed information about commitments and contingencies [Line Items] | ||||||
| Estimated financial effect of contingent liabilities | SFr 90.0 | |||||
| Broadcasting Rights Penalty | ||||||
| Disclosure of detailed information about commitments and contingencies [Line Items] | ||||||
| Estimated financial effect of contingent liabilities | SFr 29.1 | |||||
| Broadcasting rights penalty, amount of claims settled | SFr 29.3 | |||||
| Dispute with Swisscome | ||||||
| Disclosure of detailed information about commitments and contingencies [Line Items] | ||||||
| Proceeds from dispute, non-prejudicial amount received | SFr 18.8 | |||||
| Gain contingencies, recognized amount | SFr 17.2 |