Statement Of Changes In Net Assets Available For Benefits [Abstract]
| Concept | 2021-01-01 to 2021-12-31 | 2020-01-01 to 2020-12-31 | 
|---|---|---|
| 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 | 
                                                2,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                5,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Tax expense (income) | 
                                                1 186
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             |