Employees
| Concept | 
                                    
                                        As at 2024-12-31  | 
                            
                                
                                    
                                        As at 2024-12-31  | 
                            
                                
                                    
                                        As at 2024-12-31  | 
                            
                        
|---|---|---|---|
| Employees | |||
| Metrics related to human capital diversity | |||
| Metrics of consolidated subsidiaries | |||
| Consolidated subsidiaries | 
                                        
                                             
                                                ㈱スミカワADD
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                ㈱エー・ディー・パートナーズ
                                                
                                             
                                        
                                     | 
                                
                                    
                                        
                                             
                                                ㈱エー・ディー・ワークス
                                                
                                             
                                        
                                     | 
                                
                            
| Ratio of female employees in managerial positions | 
                                        
                                             
                                                0.333
                                                
                                                    
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                                     | 
                                
                                    
                                        
                                             
                                                0.375
                                                
                                                    
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                                     | 
                                
                                    
                                        
                                             
                                                0.152
                                                
                                                    
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                                     | 
                                
                            
| Ratio of male employees taking childcare leave | |||
| All employees | 
                                        
                                             
                                                0.000
                                                
                                                    
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                                     | 
                                
                                    
                                        
                                             
                                                
                                                
                                                    
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                                     | 
                                
                            
| Differences in wages between male and female employees | |||
| All employees | 
                                        
                                             
                                                0.834
                                                
                                                    
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                                     | 
                                
                                    
                                        
                                             
                                                0.648
                                                
                                                    
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                                     | 
                                
                                    
                                        
                                             
                                                0.618
                                                
                                                    
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                                     | 
                                
                            
| Regular employees | 
                                        
                                             
                                                0.847
                                                
                                                    
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                                     | 
                                
                                    
                                        
                                             
                                                0.731
                                                
                                                    
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                                     | 
                                
                                    
                                        
                                             
                                                0.653
                                                
                                                    
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                                     | 
                                
                            
| Non-regular employees | 
                                        
                                             
                                                0.735
                                                
                                                    
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                                     | 
                                
                                    
                                        
                                             
                                                0.180
                                                
                                                    
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                                     | 
                                
                                    
                                        
                                             
                                                0.405
                                                
                                                    
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                                     |