Semi-Annual Consolidated Statement Of Cash Flows
| Concept | 2024-01-01 to 2024-12-31 | As at 2024-12-31 | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | As at 2022-12-31 | 
|---|---|---|---|---|---|
| Semi-annual consolidated statement of cash flows | |||||
| Statement of cash flows | |||||
| Cash flows from operating activities | |||||
| Subtotal | 
                                                4,334,890,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,697,600,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | 
                                                62,115,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                41,919,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | 
                                                -7,170,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -7,023,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Compensation paid for damage | 
                                                -60,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | 
                                                -537,033,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,894,270,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                4,005,658,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -160,001,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | |||||
| Purchase of property, plant and equipment | 
                                                -1,207,364,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,676,507,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of property, plant and equipment | 
                                                6,323,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,234,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of investment securities | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -18,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of investment securities | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Loan advances | 
                                                -4,600,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from collection of loans receivable | 
                                                2,400,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,485,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                50,430,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                28,075,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | 
                                                -1,160,667,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,664,683,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | |||||
| Repayments of long-term borrowings | 
                                                -200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of treasury shares | 
                                                -75,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -102,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Dividends paid | 
                                                -463,573,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -320,874,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                -1,367,914,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                169,481,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                -4,265,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -9,541,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Effect of exchange rate change on cash and cash equivalents | 
                                                2,846,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,595,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                1,479,923,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,651,608,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                3,773,561,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,293,638,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,945,246,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |