Disclosure Of Leases [Text Block]
| Concept | As at 2024-12-31 | 2024-01-01 to 2024-12-31 | As at 2023-12-31 | 
|---|---|---|---|
| Disclosure of leases [text block] | — |  | — | 
| Presentation of leases for lessee [abstract] | |||
| Right-of-use assets | 
                                                79,000,000
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | 
                                                93,000,000
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | 
| Lease liabilities [abstract] | |||
| Current lease liabilities | 
                                                23,000,000
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | 
                                                21,000,000
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | 
| Non-current lease liabilities | 
                                                65,000,000
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | — | 
                                                75,000,000
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | 
| Disclosure of quantitative information about leases for lessee [abstract] | |||
| Disclosure of quantitative information about right-of-use assets [text block] | — | — | — | 
| Disclosure of quantitative information about right-of-use assets [abstract] | |||
| Disclosure of quantitative information about right-of-use assets [line items] | |||
| Reconciliation of changes in right-of-use assets [abstract] |