Consolidated Statement Of Changes In Equity
| Concept | As at 2023-12-31 | 2023-04-01 to 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | 2023-04-01 to 2023-12-31 | As at 2023-12-31 | 2023-04-01 to 2023-12-31 | 2023-04-01 to 2023-12-31 | 2023-04-01 to 2023-12-31 | 2023-04-01 to 2023-12-31 | 2023-04-01 to 2023-12-31 | 2023-04-01 to 2023-12-31 | 2023-04-01 to 2023-12-31 | As at 2023-12-31 | 2023-04-01 to 2023-12-31 | 2023-10-01 to 2023-12-31 | 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 2022-12-31 | 2022-04-01 to 2022-12-31 | As at 2022-12-31 | As at 2022-12-31 | As at 2022-12-31 | 2022-10-01 to 2022-12-31 | As at 2022-12-31 | As at 2022-12-31 | As at 2022-12-31 | As at 2022-12-31 | As at 2022-12-31 | 2022-04-01 to 2022-12-31 | 2022-04-01 to 2022-12-31 | 2022-04-01 to 2022-12-31 | 2022-04-01 to 2022-12-31 | 2022-04-01 to 2022-12-31 | 2022-04-01 to 2022-12-31 | As at 2022-12-31 | 2022-04-01 to 2022-12-31 | 2022-04-01 to 2022-12-31 | 2022-04-01 to 2022-12-31 | As at 2022-03-31 | As at 2022-03-31 | As at 2022-03-31 | As at 2022-03-31 | As at 2022-03-31 | As at 2022-03-31 | As at 2022-03-31 | As at 2022-03-31 | As at 2022-03-31 | As at 2022-03-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Consolidated statement of changes in equity | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Statement of changes in equity | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Equity | 
                                                11,411,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                215,316,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                309,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                196,457,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -577,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                215,007,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,174,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,445,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                11,988,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                -2,480,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                180,433,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,174,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,445,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -616,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                195,933,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,052,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                195,625,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,480,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                307,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,669,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                195,968,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,479,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,174,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                195,660,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                307,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,445,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -606,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,114,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                180,406,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                8,720,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                180,585,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,478,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                300,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,394,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,140,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                165,303,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                5,174,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                180,886,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,445,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -253,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Comprehensive income | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Profit (loss) | — | 
                                                1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,002,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,002,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                24,004,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,827,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                22,681,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                7,453,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                7,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                22,674,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                22,674,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Other comprehensive income | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,394,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                39,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,355,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,394,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,394,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -109,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                214,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                850,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                566,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -352,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                214,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                214,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Comprehensive income | — | 
                                                1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                27,397,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                39,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,002,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,355,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,394,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                27,398,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,718,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | 
                                                22,895,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                8,304,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                7,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                22,674,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                566,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -352,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                22,888,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                214,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Transactions with owners | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Purchase of treasury shares | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Dividends | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -8,014,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -8,014,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -8,014,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                -7,812,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -7,812,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -7,812,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | 
| Total transactions with owners | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -8,015,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -7,978,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -36,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -36,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -8,015,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                -7,813,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -7,571,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -241,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -7,813,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -241,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — |