Employees
| Concept | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | 
|---|---|---|---|---|---|---|
| Employees | ||||||
| Metrics related to human capital diversity | ||||||
| Metrics of consolidated subsidiaries | ||||||
| Consolidated subsidiaries | 
                                                ㈱羽田エアポートエンタープライズ
                                                
                                             | 
                                                日本空港テクノ㈱
                                                
                                             | 
                                                東京エアポートレストラン㈱
                                                
                                             | 
                                                羽田エアポートセキュリティー㈱
                                                
                                             | 
                                                コスモ企業㈱
                                                
                                             | 
                                                ㈱日本空港ロジテム
                                                
                                             | 
| Ratio of female employees in managerial positions | 
                                                0.759
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.186
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.125
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.286
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Ratio of male employees taking childcare leave | ||||||
| All employees | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.857
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.750
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.800
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Regular employees | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.857
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.750
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.800
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Non-regular employees | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Differences in wages between male and female employees | ||||||
| All employees | 
                                                0.843
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.738
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.745
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.910
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.726
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.701
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Regular employees | 
                                                0.858
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.842
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.742
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.838
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.851
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.988
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Non-regular employees | 
                                                0.687
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.789
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.826
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.779
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.872
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |