| 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 | 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 | 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 | 
                                                中電技術コンサルタント㈱
                                                
                                             | 
                                                エネルギア・パワー山口㈱
                                                
                                             | 
                                                ㈱エネルギア・ソリューション・アンド・サービス
                                                
                                             | 
                                                ㈱エネルギアL&Bパートナーズ
                                                
                                             | 
                                                中国高圧コンクリート工業㈱
                                                
                                             | 
                                                ㈱エネルギア・ビジネスサービス
                                                
                                             | 
                                                中国計器工業㈱
                                                
                                             | 
                                                中国電力ネットワーク㈱
                                                
                                             | 
                                                ㈱パワー・エンジニアリング・アンド・トレーニングサービス
                                                
                                             | 
                                                中電環境テクノス㈱
                                                
                                             | 
                                                ㈱電力サポート中国
                                                
                                             | 
                                                ㈱エネコム
                                                
                                             | 
                                                ㈱エネルギア・ロジスティックス
                                                
                                             | 
                                                中電工業㈱
                                                
                                             | 
                                                ㈱アドプレックス
                                                
                                             | 
                                                中電プラント㈱
                                                
                                             | 
| Ratio of female employees in managerial positions | 
                                                0.084
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.000
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.000
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.000
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.059
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.035
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.003
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.000
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.053
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.000
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.035
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.000
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.000
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.038
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.026
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Ratio of male employees taking childcare leave | ||||||||||||||||
| All employees | 
                                                0.800
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1.000
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1.000
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.330
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.520
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.200
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.000
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.640
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Regular employees | — | — | 
                                                1.000
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.500
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                0.920
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
| Differences in wages between male and female employees | ||||||||||||||||
| All employees | 
                                                0.653
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.737
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.752
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.575
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.918
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.907
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.766
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.601
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.897
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.885
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.655
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.761
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.853
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.755
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.792
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.724
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Regular employees | 
                                                0.780
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.737
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.742
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.800
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.908
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.892
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.766
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.595
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.634
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.860
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.838
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.754
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.807
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.785
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.769
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.859
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Non-regular employees | 
                                                0.568
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.672
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.358
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1.022
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.811
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.895
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.717
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.588
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.591
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1.014
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.433
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1.296
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.773
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |