Subclassifications Of Assets, Liabilities And Equities [Abstract]
| Concept | As at 2023-12-31 | As at 2022-12-31 | 
|---|---|---|
| Subclassifications of assets, liabilities and equities [abstract] | ||
| Property, plant and equipment [abstract] | ||
| Property, plant and equipment | 
                                                321,843,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                320,979,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Intangible assets and goodwill [abstract] | ||
| Intangible assets other than goodwill [abstract] | ||
| Intangible assets other than goodwill | 
                                                2,419,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                2,341,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Goodwill | 
                                                4,329,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                4,329,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Investment property [abstract] | ||
| Investment property | 
                                                15,241,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                14,059,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Trade and other non-current receivables [abstract] | ||
| Other non-current receivables | 
                                                78,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                24,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Trade and other current receivables [abstract] | ||
| Trade and other current receivables | 
                                                8,179,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                11,229,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Current prepayments and current accrued income including current contract assets [abstract] | ||
| Current accrued income including current contract assets [abstract] | ||
| Current contract assets | 
                                                1,079,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                1,444,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Classes of current inventories [abstract] | ||
| Current inventories | 
                                                19,576,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                21,736,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Classes of current inventories, alternative [abstract] | ||
| Cash and cash equivalents [abstract] | ||
| Cash and cash equivalents | 
                                                56,938,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                45,374,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Non-current assets or disposal groups classified as held for sale or as held for distribution to owners [abstract] | ||
| Non-current assets or disposal groups classified as held for sale or as held for distribution to owners | 
                                                -
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                1,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Classes of other provisions [abstract] | ||
| Other provisions [abstract] | ||
| Other current provisions | 
                                                10,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                10,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Non-current portion of non-current borrowings, by type [abstract] | ||
| Non-current portion of non-current loans received | — | — | 
| Non-current portion of non-current secured bank loans received | 
                                                15,142,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                5,575,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Current borrowings and current portion of non-current borrowings, by type [abstract] | ||
| Current loans received and current portion of non-current loans received | — | — | 
| Current secured bank loans received and current portion of non-current secured bank loans received | 
                                                3,459,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                3,455,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Trade and other non-current payables [abstract] | ||
| Non-current accruals and non-current deferred income including non-current contract liabilities [abstract] | ||
| Non-current deferred income including non-current contract liabilities [abstract] | ||
| Non-current deferred income other than non-current contract liabilities | — | — | 
| Non-current government grants | 
                                                1,115,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                1,156,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Other non-current payables | 
                                                152,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                109,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Trade and other current payables [abstract] | ||
| Current accruals and current deferred income including current contract liabilities [abstract] | ||
| Current deferred income including current contract liabilities [abstract] | ||
| Current contract liabilities [abstract] | ||
| Current contract liabilities | 
                                                2,819,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                3,938,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Current deferred income other than current contract liabilities | — | — | 
| Current government grants | 
                                                107,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                107,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Trade and other current payables | 
                                                10,475,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                13,135,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Issued capital [abstract] | ||
| Issued capital | 
                                                96,808,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                96,808,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Retained earnings [abstract] | ||
| Retained earnings | 
                                                149,388,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                142,576,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Accumulated other comprehensive income [abstract] | ||
| Reserve of exchange differences on translation | 
                                                20,393,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                24,607,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Net assets (liabilities) [abstract] | ||
| Assets | 
                                                432,419,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                421,695,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Liabilities | 
                                                48,620,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                40,468,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Net current assets (liabilities) [abstract] | ||
| Current liabilities | 
                                                17,354,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                20,949,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Assets less current liabilities [abstract] |