Statement Of Cash Flows
| Concept | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2023-03-31 | 
|---|---|---|---|---|---|
| Statement of cash flows | |||||
| Statement of cash flows | |||||
| Cash flows from operating activities | |||||
| Subtotal | — | 
                                                393,211,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,193,555,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Income taxes paid | — | 
                                                -16,954,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -23,931,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | 
                                                376,257,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,217,487,000,000
                                                
                                                    
                                                        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 | — | 
                                                -10,175,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -9,353,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of property, plant and equipment | — | 
                                                820,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,458,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Other, net | — | 
                                                -370,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -150,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from investing activities | |||||
| Purchase of securities | — | 
                                                -879,606,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -868,067,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Proceeds from sale of securities | — | 
                                                466,168,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                554,388,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) investing activities | — | 
                                                21,589,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                37,479,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash flows from financing activities | |||||
| Purchase of treasury shares | — | 
                                                -20,002,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -7,002,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Dividends paid | — | 
                                                -29,164,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -24,122,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -70,611,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -51,025,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Effect of exchange rate change on cash and cash equivalents | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                327,234,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                -2,231,033,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Cash and cash equivalents | 
                                                4,353,143,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                4,025,908,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,256,941,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |