Statement Of Cash Flows [Abstract]
| Concept | 
                                    
                                        2023-01-01 to 2023-12-31  | 
                            
                                
                                    
                                        2022-01-01 to 2022-12-31  | 
                            
                        
|---|---|---|
| Statement of cash flows [abstract] | ||
| Cash flows from (used in) operating activities [abstract] | ||
| Adjustments for dividend income | 
                                        
                                             
                                                2,348,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                633,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Adjustments for increase (decrease) in other liabilities | 
                                        
                                             
                                                4,282,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                80,959,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Adjustments for decrease (increase) in financial assets measured at fair value through profit or loss | — | — | 
| Adjustments for decrease (increase) in financial assets at fair value through profit or loss, mandatorily measured at fair value | — | — | 
| Adjustments for decrease (increase) in financial assets held for trading | 
                                        
                                             
                                                653,063,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                525,578,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Adjustments for decrease (increase) in loans and advances | — | — | 
| Adjustments for decrease (increase) in loans and advances to banks | 
                                        
                                             
                                                7,511,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                2,177,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Adjustments for decrease (increase) in loans and advances to customers | 
                                        
                                             
                                                1,111,264,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                402,207,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Adjustments for increase (decrease) in deposits | — | — | 
| Adjustments for increase (decrease) in deposits from banks | 
                                        
                                             
                                                3,617,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                4,830,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Adjustments for increase (decrease) in deposits from customers | 
                                        
                                             
                                                859,780,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                1,487,692,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Adjustments for depreciation and amortisation expense and impairment loss (reversal of impairment loss) recognised in profit or loss | 
                                        
                                             
                                                14,296,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                12,959,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Adjustments for gains (losses) on fair value adjustment, investment property | 
                                        
                                             
                                                -
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                14,769,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Cash flows from (used in) investing activities [abstract] | ||
| Purchase of property, plant and equipment, intangible assets other than goodwill, investment property and other non-current assets | 
                                        
                                             
                                                29,490,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                42,001,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Proceeds from disposals of property, plant and equipment, intangible assets other than goodwill, investment property and other non-current assets | 
                                        
                                             
                                                231,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                25,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             
                                        
                                     |