Semi-Annual Consolidated Balance Sheet
| Concept | As at 2024-06-30 | 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 | 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 | 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 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 | 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 | 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 | 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 | As at 2022-12-31 | As at 2022-12-31 | As at 2021-12-31 | As at 2021-12-31 | As at 2021-12-31 | As at 2021-12-31 | As at 2021-12-31 | As at 2021-12-31 | As at 2021-12-31 | As at 2021-12-31 | As at 2021-12-31 | As at 2021-12-31 | As at 2021-12-31 | As at 2021-12-31 | As at 2021-12-31 | As at 2021-12-31 | As at 2021-12-31 | As at 2021-12-31 | As at 2021-12-31 | As at 2021-12-31 | As at 2021-12-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Semi-annual consolidated balance sheet | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Balance sheet | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Assets | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Current assets | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Cash and deposits | 
                                                7,451,528,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                6,268,044,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                3,922,167,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                5,731,142,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                3,178,280,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Other | 
                                                445,384,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                380,108,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                164,850,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                370,396,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                143,627,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Current assets | 
                                                15,341,180,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                14,366,369,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                9,227,251,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                12,971,466,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                8,439,859,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Non-current assets | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Property, plant and equipment | 
                                                2,402,563,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,042,863,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                112,916,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                1,734,562,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                136,599,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Property, plant and equipment | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Buildings and structures | — | — | — | — | — | 
                                                4,151,779,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                4,044,207,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Accumulated depreciation | — | — | — | — | — | 
                                                -3,046,900,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                -3,120,455,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Buildings and structures, net | 
                                                1,275,651,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,104,878,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                923,751,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Leased assets | — | — | — | — | — | 
                                                923,695,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                1,050,503,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Accumulated depreciation | — | — | — | — | — | 
                                                -593,922,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                -807,040,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Leased assets, net | 
                                                355,309,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                329,772,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                243,462,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Construction in progress | 
                                                44,051,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                9,085,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                8,267,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Intangible assets | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Other | 
                                                26,673,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                31,220,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                389,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                31,236,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                389,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Intangible assets | 
                                                574,305,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                571,696,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                507,664,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                493,310,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                463,117,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Investments and other assets | 
                                                3,109,837,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                3,089,365,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                6,103,723,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                2,952,397,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                5,960,762,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Investments and other assets | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Deferred tax assets | 
                                                883,339,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                793,652,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                465,491,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                713,174,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                573,781,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Other | 
                                                45,210,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                45,766,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                27,441,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                46,113,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                25,154,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Allowance for doubtful accounts | 
                                                -11,996,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -12,256,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                -12,571,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Non-current assets | 
                                                6,086,706,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                5,703,925,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                6,724,305,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                5,180,271,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                6,560,479,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Assets | 
                                                21,427,886,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,011,642,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                21,261,793,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                20,070,294,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                15,951,556,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                -1,191,498,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                20,250,151,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                18,151,737,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                18,205,549,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                15,000,339,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                -702,094,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                18,853,832,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                648,283,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Liabilities | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Current liabilities | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Short-term borrowings | 
                                                2,900,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,900,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2,100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                2,900,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                2,100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Lease liabilities | 
                                                114,979,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                122,023,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                112,579,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Income taxes payable | 
                                                1,071,615,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                456,062,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                425,787,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                412,355,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                384,145,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Other | 
                                                482,098,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                409,736,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                198,792,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                354,708,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                48,634,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Current liabilities | 
                                                10,321,891,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                9,700,625,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                5,568,807,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                9,785,529,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                6,054,016,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Non-current liabilities | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Long-term borrowings | 
                                                3,246,250,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                3,643,750,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                3,643,750,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                3,975,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                3,975,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Lease liabilities | 
                                                300,681,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                279,255,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                206,606,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Other | 
                                                10,299,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Non-current liabilities | 
                                                3,639,750,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                3,995,605,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                3,658,750,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                4,249,686,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                3,990,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Liabilities | 
                                                13,961,642,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,142,424,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,434,401,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                13,696,230,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                9,227,557,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                -738,170,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                13,291,977,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                14,035,216,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                13,535,721,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                10,044,016,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | 
                                                -503,017,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                14,538,233,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,002,511,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Net assets | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Shareholders' equity | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Share capital | 
                                                220,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                220,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                220,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                220,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                220,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Capital surplus | 
                                                150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Retained earnings | 
                                                10,980,884,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                9,862,074,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                10,329,007,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                7,611,734,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                8,561,332,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Treasury shares | 
                                                -3,975,008,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -3,975,008,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -3,975,008,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                -3,975,008,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -3,975,008,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Shareholders' equity | 
                                                7,375,875,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                6,257,065,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                6,723,998,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                4,006,725,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                4,956,323,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Valuation and translation adjustments | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Foreign currency translation adjustment | 
                                                90,368,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                116,997,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                109,796,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Valuation and translation adjustments | 
                                                90,368,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                116,997,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
                                                109,796,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 
| Net assets | 
                                                7,466,244,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -3,975,008,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                116,997,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,374,063,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                220,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,257,065,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                116,997,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                220,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,723,998,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,862,074,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                10,329,007,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,723,998,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,975,008,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                10,329,007,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,116,521,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,006,725,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,561,332,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -3,975,008,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,956,323,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,956,323,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,611,734,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -3,975,008,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                220,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                220,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                109,796,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                8,561,332,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                109,796,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                81,210,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                132,216,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,432,315,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,883,526,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,541,035,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                81,210,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                81,210,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                51,006,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                220,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                220,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,432,315,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,408,819,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,802,315,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,038,819,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Liabilities and net assets | 
                                                21,427,886,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                20,070,294,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                15,951,556,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | 
                                                18,151,737,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                15,000,339,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |