Quarterly Statement Of Cash Flows
| Concept | As at 2024-06-30 | 2024-01-01 to 2024-06-30 | As at 2023-12-31 | As at 2023-06-30 | 2023-01-01 to 2023-06-30 | As at 2022-12-31 | 
|---|---|---|---|---|---|---|
| Quarterly statement of cash flows | ||||||
| Statement of cash flows | ||||||
| Cash flows from operating activities | ||||||
| Subtotal | — | 
                                                754,785,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                818,234,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | — | 
                                                481,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                253,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                570,896,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                819,572,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | ||||||
| Purchase of property, plant and equipment | — | 
                                                -19,973,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -125,319,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of investment securities | — | 
                                                -598,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -600,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -24,191,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -124,999,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | ||||||
| Dividends paid | — | 
                                                -458,760,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -526,604,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -458,760,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -526,604,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                87,944,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                167,968,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                1,333,924,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,245,980,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,855,832,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                1,687,864,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |