Quarterly Consolidated Statement Of Cash Flows
| Concept | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | As at 2022-03-31 | 
|---|---|---|---|---|---|
| Quarterly consolidated statement of cash flows | |||||
| Statement of cash flows | |||||
| Cash flows from operating activities | |||||
| Subtotal | 
                                                2,930,550,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                969,376,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | 
                                                60,508,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                52,682,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | 
                                                -55,207,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -88,346,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | 
                                                2,581,432,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,047,925,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | |||||
| Purchase of property, plant and equipment | 
                                                -1,344,636,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -817,705,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of property, plant and equipment | 
                                                437,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                57,639,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of investment securities | 
                                                -946,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -515,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of investment securities | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                114,555,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of shares of subsidiaries resulting in change in scope of consolidation | 
                                                -437,975,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -290,254,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | 
                                                -21,055,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                6,253,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | 
                                                -2,528,553,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -392,066,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | |||||
| Proceeds from long-term borrowings | 
                                                952,500,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                390,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of long-term borrowings | 
                                                -831,746,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -682,428,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of treasury shares | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -96,157,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of shares of subsidiaries not resulting in change in scope of consolidation | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -94,950,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -4,950,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | 
                                                888,628,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -867,063,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Effect of exchange rate change on cash and cash equivalents | 
                                                66,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                49,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                941,573,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -211,153,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                3,953,645,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,012,071,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                3,223,225,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |