Quarterly 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 | 
|---|---|---|---|---|---|
| Quarterly statement of cash flows | |||||
| Statement of cash flows | |||||
| Cash flows from operating activities | |||||
| Subtotal | 
                                                3,228,940,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,563,652,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | 
                                                35,007,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                31,225,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | 
                                                -65,755,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -49,726,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | 
                                                -352,554,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -633,339,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                2,845,638,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,915,190,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | |||||
| Purchase of property, plant and equipment | 
                                                -3,314,592,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,881,422,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of property, plant and equipment | 
                                                617,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                7,748,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of investment securities | 
                                                -2,444,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,221,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                -6,298,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,201,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | 
                                                -3,365,524,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,897,286,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | |||||
| Proceeds from long-term borrowings | 
                                                1,194,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                855,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of long-term borrowings | 
                                                -669,545,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -714,433,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of treasury shares | 
                                                -52,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Dividends paid | 
                                                -989,395,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,098,920,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                1,435,194,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,314,445,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Effect of exchange rate change on cash and cash equivalents | 
                                                167,800,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                84,933,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                1,083,109,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -2,211,608,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                5,105,300,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,022,190,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,233,799,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |