Profit Or Loss [Abstract]
| Concept | 
                                    
                                        2023-01-01 to 2023-12-31  | 
                            
                                
                                    
                                        2022-01-01 to 2022-12-31  | 
                            
                        
|---|---|---|
| Profit or loss [abstract] | ||
| Profit (loss) [abstract] | ||
| Revenue | 
                                        
                                             
                                                837  523
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                79 7    116
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Profit (loss) from operating activities | 
                                        
                                             
                                                10 4   55 6
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                87  929
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Finance income | 
                                        
                                             
                                                3 503
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                4 47
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Finance costs | 
                                        
                                             
                                                1   208
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                1  362
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Profit (loss) before tax | 
                                        
                                             
                                                106  851
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                87  014
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Tax expense (income) | 
                                        
                                             
                                                22  810
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                18  790
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Profit (loss) | 
                                        
                                             
                                                84  0 41
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                68  224
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Profit (loss), attributable to [abstract] | ||
| Profit (loss), attributable to owners of parent | 
                                        
                                             
                                                84  0 41
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                68  224
                                                
                                                    
                                                        SEK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Earnings per share [text block] | — | — | 
| Earnings per share [abstract] | ||
| Earnings per share [line items] | ||
| Diluted earnings per share [abstract] | ||
| Diluted earnings (loss) per share | 
                                        
                                             
                                                1 ,60
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                1, 3 0
                                                
                                             
                                        
                                     |