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 | 
|---|---|---|---|---|---|
| Statement of cash flows | |||||
| Statement of cash flows | |||||
| Cash flows from operating activities | |||||
| Subtotal | 
                                                12,378,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                14,600,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest and dividends received | 
                                                125,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                78,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Interest paid | 
                                                -1,134,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,194,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | 
                                                -1,022,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -959,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | 
                                                10,364,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                12,536,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from operating activities | |||||
| Cash flows from operating activities | |||||
| Cash flows from facilities maintenance and investing activities | |||||
| Purchase of property, plant and equipment | 
                                                -7,142,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -5,079,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of property, plant and equipment | 
                                                114,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                -199,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                89,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | |||||
| Net cash provided by (used in) investing activities | 
                                                -9,843,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -6,593,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | |||||
| Purchase of treasury shares | 
                                                -3,070,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -185,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Dividends paid | 
                                                -1,249,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -752,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from long-term borrowings | 
                                                8,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                13,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | 
                                                -7,743,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -5,197,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Repayments of long-term borrowings | 
                                                -8,900,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -6,180,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | 
                                                115,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -14,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Effect of exchange rate change on cash and cash equivalents | 
                                                10,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                -7,213,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                746,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | — | 
                                                19,361,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                26,406,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                25,660,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |