Statement Of Cash Flows [Abstract]
| Concept | 
                                    
                                        2024-01-01 to 2024-12-31  | 
                            
                                
                                    
                                        2023-01-01 to 2023-12-31  | 
                            
                        
|---|---|---|
| Statement of cash flows [abstract] | ||
| Cash flows from (used in) operating activities [abstract] | ||
| Cash flows from (used in) operations before changes in working capital | 
                                        
                                             
                                                3,126,000,000
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                2,722,000,000
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Increase (decrease) in working capital | 
                                        
                                             
                                                176,000,000
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                438,000,000
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Adjustments for decrease (increase) in trade and other receivables | 
                                        
                                             
                                                163,000,000
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                490,000,000
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Adjustments for increase (decrease) in trade and other payables | 
                                        
                                             
                                                254,000,000
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                172,000,000
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Adjustments for depreciation and amortisation expense and impairment loss (reversal of impairment loss) recognised in profit or loss | 
                                        
                                             
                                                1,379,000,000
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                1,729,000,000
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Cash flows from (used in) investing activities [abstract] | ||
| Payments for development project expenditure | 
                                        
                                             
                                                1,015,000,000
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                951,000,000
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Cash flows from (used in) financing activities [abstract] | ||
| Proceeds from exercise of options | 
                                        
                                             
                                                -
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                47,000,000
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Repayments of non-current borrowings | 
                                        
                                             
                                                32,000,000
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                -
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Cash flows from (used in) increase (decrease) in current borrowings | 
                                        
                                             
                                                258,000,000
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                -
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     | 
                                
                            
| Repayments of bonds, notes and debentures | 
                                        
                                             
                                                1,406,000,000
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                -
                                                
                                                    
                                                        DKK
                                                    
                                                
                                             
                                        
                                     |