Semi-Annual Consolidated Statement Of Cash Flows
| Concept | 2024-01-01 to 2024-06-30 | As at 2024-06-30 | As at 2023-12-31 | 2023-01-01 to 2023-06-30 | As at 2023-06-30 | As at 2022-12-31 | 
|---|---|---|---|---|---|---|
| Semi-annual consolidated statement of cash flows | ||||||
| Statement of cash flows | ||||||
| Cash flows from operating activities | ||||||
| Subtotal | 
                                                174,020,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                498,972,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | 
                                                803,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                789,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | 
                                                -2,950,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -4,059,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | 
                                                -25,197,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -55,959,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                158,074,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                359,081,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | ||||||
| Purchase of property, plant and equipment | 
                                                -2,996,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -418,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of property, plant and equipment | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                68,152,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Purchase of shares of subsidiaries resulting in change in scope of consolidation | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -51,117,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                -555,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -38,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | 
                                                -18,790,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                7,849,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | ||||||
| Proceeds from long-term borrowings | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                100,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of long-term borrowings | 
                                                -123,420,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -147,205,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Dividends paid | 
                                                -34,021,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -24,396,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                -211,316,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                16,552,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                -72,032,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                383,483,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                2,452,504,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,524,536,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,888,750,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,505,267,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |