Quarterly Consolidated Balance Sheet
| Concept | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-09-30 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-09-30 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Quarterly consolidated balance sheet | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Balance sheet | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Assets | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Non-current assets | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Property, plant and equipment | — | — | — | — | — | — | — | 
                                                38,132,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                34,977,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                36,110,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                32,944,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Property, plant and equipment | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Accumulated depreciation | — | — | — | — | — | — | — | 
                                                -21,255,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                -20,670,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Intangible assets | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Goodwill | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                132,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                132,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                132,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Intangible assets | — | — | — | — | — | — | — | 
                                                3,766,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                3,574,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                3,307,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,106,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Investments and other assets | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Deferred tax assets | — | — | — | — | — | — | — | 
                                                5,200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                4,115,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                4,569,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,620,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Assets | — | — | — | — | 
                                                160,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,075,110,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,031,908,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                2,990,611,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,074,950,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -43,202,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                2,990,370,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                7,913,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                23,016,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,562,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                47,086,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                3,067,017,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,027,311,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                182,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,008,190,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                3,047,322,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -39,132,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,047,140,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                22,335,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,966,401,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                44,159,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,211,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,032,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Liabilities | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Current liabilities | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Income taxes payable | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                1,363,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                1,136,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Non-current liabilities | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Retirement benefit liability | — | — | — | — | — | — | — | 
                                                580,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                565,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Liabilities | — | — | — | — | 
                                                3,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,928,017,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,888,588,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                2,866,061,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,928,014,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -39,428,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                2,865,484,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,791,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                15,062,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,357,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                39,318,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                2,924,453,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                2,903,123,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                54,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,869,947,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                2,905,356,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -35,408,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,905,302,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                14,607,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,845,692,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                36,643,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,380,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,979,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Net assets | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Shareholders' equity | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Share capital | — | — | — | — | — | — | — | 
                                                56,967,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                56,967,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                56,967,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                56,967,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Capital surplus | — | — | — | — | — | — | — | 
                                                14,260,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                12,922,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                14,244,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                12,906,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Retained earnings | — | — | — | — | — | — | — | 
                                                75,536,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                58,457,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                72,797,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                56,111,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Treasury shares | — | — | — | — | — | — | — | 
                                                -1,839,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                -1,839,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                -1,417,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -1,417,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Shareholders' equity | — | — | — | — | — | — | — | 
                                                144,924,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                126,507,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                142,590,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                124,567,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Valuation and translation adjustments | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Valuation difference on available-for-sale securities | — | — | — | — | — | — | — | 
                                                -2,771,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                -2,789,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                -1,223,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -1,239,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Revaluation reserve for land | — | — | — | — | — | — | — | 
                                                796,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                796,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                796,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                796,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Remeasurements of defined benefit plans | — | — | — | — | — | — | — | 
                                                335,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                337,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Valuation and translation adjustments | — | — | — | — | — | — | — | 
                                                -1,639,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                -1,993,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                -90,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                -443,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Share acquisition rights | — | — | — | — | — | — | — | 
                                                35,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                35,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                64,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                64,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Net assets | 
                                                -1,839,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                58,457,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                796,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                335,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,789,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                143,320,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                35,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,993,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                56,967,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                54,243,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                126,507,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,840,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                124,550,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,922,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,213,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                56,967,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                75,536,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                35,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,839,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                82,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,771,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                144,924,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,639,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,260,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                796,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                64,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                56,967,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                337,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                124,567,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,840,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,417,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                56,111,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,239,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -443,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,223,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,244,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,059,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                72,797,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                52,051,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,906,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,417,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                66,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                56,967,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                142,564,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                142,590,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                64,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -90,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                124,187,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                796,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                796,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                804,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                56,967,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                51,686,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -4,271,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                138,242,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,417,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                55,591,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,466,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,417,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,390,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                63,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                64,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                120,645,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,840,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,906,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                124,048,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,905,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                56,967,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                66,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                141,568,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -4,258,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,244,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                71,774,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                64,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                804,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                160,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -290,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,151,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                52,986,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,759,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                56,967,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                56,967,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                49,226,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                47,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -346,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                138,292,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                121,121,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,148,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,225,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,887,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,534,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -1,534,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                52,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                12,840,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                138,162,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                121,307,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                68,634,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                160,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                804,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                804,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | — | — | — | — | — | — | — | 
                                                3,031,908,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                2,990,611,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                3,067,017,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                3,027,311,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |