Statement Of Cash Flows [Abstract]
| Concept | 2021-01-01 to 2021-12-31 | 2020-01-01 to 2020-12-31 | 
|---|---|---|
| Statement of cash flows [abstract] | ||
| Cash flows from (used in) investing activities [abstract] | ||
| Proceeds from sales of investments other than investments accounted for using equity method | 
                                                5 912
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Inflows of cash from investing activities | 
                                                180,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             |