Disclosure Of Entity's Operating Segments [Text Block]
| Concept | 2021-01-01 to 2021-12-31 | 2021-01-01 to 2021-12-31 | As at 2021-12-31 | 2021-01-01 to 2021-12-31 | 2021-01-01 to 2021-12-31 | 2021-01-01 to 2021-12-31 | 2021-01-01 to 2021-12-31 | 2021-01-01 to 2021-12-31 | 2021-01-01 to 2021-12-31 | 2021-01-01 to 2021-12-31 | 2020-01-01 to 2020-12-31 | 2020-01-01 to 2020-12-31 | 2020-01-01 to 2020-12-31 | 2020-01-01 to 2020-12-31 | As at 2020-12-31 | 2020-01-01 to 2020-12-31 | 2020-01-01 to 2020-12-31 | 2020-01-01 to 2020-12-31 | 2020-01-01 to 2020-12-31 | 2020-01-01 to 2020-12-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Disclosure of entity's operating segments [text block] | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disclosure of operating segments [text block] | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Disclosure of operating segments [abstract] | ||||||||||||||||||||
| Disclosure of operating segments [line items] | ||||||||||||||||||||
| Interest income | — | — | — | — | — | — | — | — | — | 
                                                130,297,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                135,804,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Interest expense | — | — | — | — | — | — | — | — | — | 
                                                16,129,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                17,471,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Interest income (expense) | — | — | — | — | — | — | — | — | — | 
                                                114,168,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                118,333,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Tax expense (income) | — | — | — | — | — | — | — | — | — | 
                                                2,452,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                2,430,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Profit (loss) before tax | — | — | — | — | — | — | — | — | — | 
                                                29,408,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                23,264,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Profit (loss) | 
                                                9,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                26,965,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | 
                                                -
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                26,965,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                26,956,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                20,834,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                20,880,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | 
                                                -
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                46,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                20,880,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
| Assets | — | — | 
                                                7,701,310,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                6,930,418,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | — | — | — | — | 
| Liabilities | — | — | 
                                                7,093,361,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                6,344,613,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | — | — | — | — | 
| Impairment loss recognised in profit or loss | — | — | — | — | — | — | — | — | — | 
                                                6,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                -
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Cash flows from (used in) operating activities | — | — | — | — | — | — | — | — | — | 
                                                289,866,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                194,961,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Cash flows from (used in) investing activities | — | — | — | — | — | — | — | — | — | 
                                                230,683,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                106,928,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
| Cash flows from (used in) financing activities | — | — | — | — | — | — | — | — | — | 
                                                14,137,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | 
                                                13,634,000
                                                
                                                    
                                                        BGN
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — |