Statement Of Cash Flows [Abstract]
| Concept | 
                                    
                                        2021-01-01 to 2021-12-31  | 
                            
                                
                                    
                                        2020-01-01 to 2020-12-31  | 
                            
                        
|---|---|---|
| Statement of cash flows [abstract] | ||
| Cash flows from (used in) operating activities [abstract] | ||
| Cash flows from (used in) operations before changes in working capital | 
                                        
                                             
                                                1,297
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                211,000
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Increase (decrease) in working capital | 
                                        
                                             
                                                1,205
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                1,334
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Cash flows from (used in) investing activities [abstract] | ||
| Purchase of investments other than investments accounted for using equity method | 
                                        
                                             
                                                -
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                49,000
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Cash flows from (used in) decrease (increase) in short-term deposits and investments | 
                                        
                                             
                                                4,751
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                9,373
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Cash flows from (used in) financing activities [abstract] | ||
| Proceeds from non-current borrowings | 
                                        
                                             
                                                146,000
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                8,000
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Cash flows from (used in) increase (decrease) in current borrowings | 
                                        
                                             
                                                4,117
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                8,907
                                                
                                                    
                                                        iso4217:HRK
                                                    
                                                
                                             
                                        
                                     |