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 deferred tax expense | 
                                                378,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                2 867
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Adjustments for decrease (increase) in other assets | 
                                                3 386
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                1 997
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Adjustments for increase (decrease) in other liabilities | 
                                                3 703
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                7 885
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Adjustments for decrease (increase) in reverse repurchase agreements and cash collateral on securities borrowed | 
                                                48 687
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                36 357
                                                
                                                    
                                                        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 | 
                                                1 020
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                95 155
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Adjustments for decrease (increase) in loans and advances | — | — | 
| Adjustments for decrease (increase) in loans and advances to customers | 
                                                231,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                149 647
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Adjustments for increase (decrease) in deposits | — | — | 
| Adjustments for increase (decrease) in deposits from banks | 
                                                2 364
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                35 221
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Adjustments for increase (decrease) in deposits from customers | 
                                                302 019
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                397 600
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Adjustments for depreciation and amortisation expense and impairment loss (reversal of impairment loss) recognised in profit or loss | 
                                                22 077
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                23 203
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Adjustments for impairment loss (reversal of impairment loss) recognised in profit or loss, property, plant and equipment | 
                                                100,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                6,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Adjustments for impairment loss (reversal of impairment loss) recognised in profit or loss, loans and advances | 
                                                6 760
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                2 802
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Adjustments for gains (losses) on fair value adjustment, investment property | 
                                                3 041
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                4 225
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             |