Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept | As at 2023-12-31 | As at 2022-12-31 | As at 2021-12-31 | 
|---|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | |||
| Property, plant and equipment [abstract] | |||
| Property, plant and equipment | 
                                                3 167
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                3 240
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | 
| Investment property [abstract] | |||
| Investment property | 
                                                94 865
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                72 536
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | 
| Trade and other current receivables [abstract] | |||
| Trade and other current receivables | 
                                                28 009
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                31 838
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | 
| Cash and cash equivalents [abstract] | |||
| Cash and cash equivalents | 
                                                416,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                78,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                397,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Borrowings [abstract] | |||
| Non-current portion of non-current borrowings | 
                                                47 330
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                48 375
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | 
| Current borrowings and current portion of non-current borrowings [abstract] | |||
| Current borrowings and current portion of non-current borrowings | 
                                                2 357
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                2 240
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | 
| Non-current portion of non-current borrowings, by type [abstract] | |||
| Current borrowings and current portion of non-current borrowings, by type [abstract] | |||
| Trade and other current payables [abstract] | |||
| Current payables to related parties | 
                                                9,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                9,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | 
| Current accruals and current deferred income including current contract liabilities [abstract] | |||
| Accruals classified as current | — | — | — | 
| Short-term employee benefits accruals | 
                                                13,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                10,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | 
| Trade and other current payables | 
                                                20 318
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                865,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | 
| Issued capital [abstract] | |||
| Issued capital | 
                                                6 925
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                6 925
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | 
| Retained earnings [abstract] | |||
| Retained earnings | 
                                                4 559
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                4 412
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | 
| Net assets (liabilities) [abstract] | |||
| Assets | 
                                                126 457
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                107 692
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | 
| Liabilities | 
                                                70 033
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                51 499
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | 
| Net current assets (liabilities) [abstract] | |||
| Current assets | 
                                                28 425
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                31 916
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | 
| Current liabilities | 
                                                22 697
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                3 124
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | 
| Assets less current liabilities [abstract] |