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 | 
                                                1,665,327,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,012,050,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | 
                                                3,973,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,889,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | 
                                                -26,657,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -32,993,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | 
                                                -291,951,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -428,661,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | 
                                                1,588,751,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,769,854,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | |||||
| Purchase of property, plant and equipment | 
                                                -583,841,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -337,025,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of property, plant and equipment | 
                                                2,668,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,794,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of investment securities | 
                                                -188,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -10,181,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of investment securities | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                150,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from collection of loans receivable | 
                                                600,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                550,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | 
                                                -1,781,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -3,395,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | 
                                                -583,063,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -561,282,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | |||||
| Proceeds from long-term borrowings | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                300,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of long-term borrowings | 
                                                -792,595,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,016,076,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of treasury shares | 
                                                -205,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -67,860,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid | 
                                                -174,141,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -175,925,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | 
                                                -1,491,616,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,439,974,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                -485,927,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -231,402,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                1,413,649,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,899,577,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                2,130,979,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |