Statement Of Cash Flows [Abstract]
| Concept | 
                                    
                                        2023-01-01 to 2023-12-31  | 
                            
                                
                                    
                                        As at 2023-12-31  | 
                            
                                
                                    
                                        2023-01-01 to 2023-12-31  | 
                            
                                
                                    
                                        2023-01-01 to 2023-12-31  | 
                            
                                
                                    
                                        As at 2022-12-31  | 
                            
                                
                                    
                                        2022-01-01 to 2022-12-31  | 
                            
                                
                                    
                                        2022-01-01 to 2022-12-31  | 
                            
                                
                                    
                                        2022-01-01 to 2022-12-31  | 
                            
                                
                                    
                                        As at 2021-12-31  | 
                            
                        
|---|---|---|---|---|---|---|---|---|---|
| Statement of cash flows [abstract] | |||||||||
| Cash flows from (used in) operating activities [abstract] | |||||||||
| Profit (loss) | 
                                        
                                             
                                                158,285,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | 
                                        
                                             
                                                712,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                157,573,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | 
                                        
                                             
                                                97,990,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                97,241,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                749,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | 
| Adjustments to reconcile profit (loss) [abstract] | |||||||||
| Adjustments for income tax expense | 
                                        
                                             
                                                19,477,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | 
                                        
                                             
                                                12,139,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | 
| Adjustments for impairment loss (reversal of impairment loss) recognised in profit or loss | 
                                        
                                             
                                                144,479,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | 
                                        
                                             
                                                140,230,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | 
| Other adjustments for non-cash items | 
                                        
                                             
                                                7,742,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | 
                                        
                                             
                                                535,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | 
| Adjustments for losses (gains) on disposal of non-current assets | 
                                        
                                             
                                                33,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | 
                                        
                                             
                                                21,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | 
| Other adjustments to reconcile profit (loss) | 
                                        
                                             
                                                322,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | 
                                        
                                             
                                                55,591,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | 
| Cash flows from (used in) operations | 
                                        
                                             
                                                77,933,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | 
                                        
                                             
                                                47,104,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | 
| Interest paid, classified as operating activities | 
                                        
                                             
                                                42,385,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | 
                                        
                                             
                                                60,197,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | 
| Interest received, classified as operating activities | 
                                        
                                             
                                                531,606,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | 
                                        
                                             
                                                425,014,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | 
| Cash flows from (used in) operating activities | 
                                        
                                             
                                                478,036,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | 
                                        
                                             
                                                1,950,474,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | 
| Cash flows from (used in) investing activities [abstract] | |||||||||
| Proceeds from sales of other long-term assets, classified as investing activities | 
                                        
                                             
                                                39,363,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | 
                                        
                                             
                                                46,128,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | 
| Income taxes paid (refund), classified as investing activities | 
                                        
                                             
                                                18,990,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | 
                                        
                                             
                                                8,333,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | 
| Cash flows from (used in) investing activities | 
                                        
                                             
                                                588,213,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | 
                                        
                                             
                                                1,698,014,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | 
| Cash flows from (used in) financing activities [abstract] | |||||||||
| Cash flows from (used in) financing activities | 
                                        
                                             
                                                322,512,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | 
                                        
                                             
                                                43,325,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | 
| Increase (decrease) in cash and cash equivalents after effect of exchange rate changes | 
                                        
                                             
                                                432,689,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | — | 
                                        
                                             
                                                209,135,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | 
| Cash and cash equivalents | — | 
                                        
                                             
                                                2,659,469,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | 
                                        
                                             
                                                2,226,780,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    — | — | — | 
                                        
                                             
                                                2,017,645,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     |