Statement Of Changes In Net Assets Available For Benefits [Abstract]
| Concept | 2023-01-01 to 2023-12-31 | 2022-01-01 to 2022-12-31 | 
|---|---|---|
| Statement of changes in net assets available for benefits [abstract] | ||
| Reconciliation of changes in net assets available for benefits [abstract] | ||
| Changes in net assets available for benefits [abstract] | ||
| Other income | 
                                                48  992
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | 
                                                25 436
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | 
| Administrative expenses | 
                                                173 624
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | 
                                                153  154
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | 
| Other expense, by function | 
                                                31 321
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | 
                                                18  619
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | 
| Tax expense (income) | 
                                                51 273
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             | 
                                                59 929
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             |