Quarterly Consolidated Statement Of Cash Flows
| Concept | As at 2024-09-30 | 2024-04-01 to 2024-09-30 | As at 2024-03-31 | As at 2023-09-30 | 2023-04-01 to 2023-09-30 | As at 2023-03-31 | 
|---|---|---|---|---|---|---|
| Quarterly consolidated statement of cash flows | ||||||
| Statement of cash flows | ||||||
| Cash flows from operating activities | ||||||
| Subtotal | — | 
                                                228,778,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                228,720,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | — | 
                                                7,199,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                8,845,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | — | 
                                                -8,083,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -7,213,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                95,881,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                110,620,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | ||||||
| Purchase of property, plant and equipment | — | 
                                                -88,587,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -89,137,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of property, plant and equipment | — | 
                                                5,396,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                78,978,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of investment securities | — | 
                                                -258,158,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -50,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of investment securities | — | 
                                                55,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of shares of subsidiaries resulting in change in scope of consolidation | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -2,815,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Loan advances | — | 
                                                -1,200,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from collection of loans receivable | — | 
                                                503,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                976,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                2,141,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                343,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -425,839,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                93,099,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | ||||||
| Repayments of long-term borrowings | — | 
                                                -126,134,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -105,262,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid | — | 
                                                -83,983,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -69,891,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -238,341,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -195,382,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Effect of exchange rate change on cash and cash equivalents | — | 
                                                -10,356,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                47,625,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                -578,656,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                55,962,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                4,182,811,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,761,467,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                4,654,984,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,599,022,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |