Analysis Of Income And Expense [Abstract]
| Concept | 
                                    
                                        2024-01-01 to 2024-12-31  | 
                            
                                
                                    
                                        2023-01-01 to 2023-12-31  | 
                            
                        
|---|---|---|
| Analysis of income and expense [abstract] | ||
| Revenue [abstract] | ||
| Dividend income | 
                                        
                                             
                                                0
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                0
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Material income and expense [abstract] | ||
| Gains (losses) on disposals of investments [abstract] | ||
| Gains on disposals of investments | 
                                        
                                             
                                                110 441
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                0
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Interest expense | 
                                        
                                             
                                                289 673
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                322 087
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Interest income (expense) | 
                                        
                                             
                                                176 414
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                251 628
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Miscellaneous other operating income | 
                                        
                                             
                                                390 501
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                209 217
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Miscellaneous other operating expense | 
                                        
                                             
                                                372 026
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                188 779
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Selling, general and administrative expense [abstract] | ||
| General and administrative expense | 
                                        
                                             
                                                282 917
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                329 481
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Fee and commission income (expense) [abstract] | ||
| Fee and commission income [abstract] | ||
| Fee and commission income | 
                                        
                                             
                                                27 258
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                22 267
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Fee and commission expense [abstract] | ||
| Fee and commission expense | 
                                        
                                             
                                                28 240
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                44 764
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Fee and commission income (expense) | 
                                        
                                             
                                                982,000
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                22 497
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Trading income (expense) [abstract] | ||
| Trading income (expense) | 
                                        
                                             
                                                425 616
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                396 407
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Expenses by nature [abstract] | ||
| Classes of employee benefits expense [abstract] | ||
| Employee benefits expense | 
                                        
                                             
                                                170 737
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                195 652
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Depreciation, amortisation and impairment loss (reversal of impairment loss) recognised in profit or loss [abstract] | ||
| Depreciation, amortisation and impairment loss (reversal of impairment loss) recognised in profit or loss | 
                                        
                                             
                                                23 358
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                33 159
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Share of profit (loss) of associates and joint ventures accounted for using equity method [abstract] | ||
| Share of profit (loss) of associates accounted for using equity method | 
                                        
                                             
                                                68 694
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                67 400
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Share of other comprehensive income of associates and joint ventures accounted for using equity method, before tax [abstract] | ||
| Share of other comprehensive income of associates and joint ventures accounted for using equity method that will not be reclassified to profit or loss, before tax | 
                                        
                                             
                                                10 195
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                57 150
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Comprehensive income, continuing and discontinued operations [abstract] | ||
| Comprehensive income | 
                                        
                                             
                                                404 601
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                322 191
                                                
                                                    
                                                        CZK
                                                    
                                                
                                             
                                        
                                     |