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 | — | 
                                                120,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,871,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | — | 
                                                69,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                56,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | — | 
                                                -16,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -19,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | — | 
                                                -483,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -488,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                -309,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,420,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | ||||||
| Purchase of property, plant and equipment | — | 
                                                -122,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -449,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of property, plant and equipment | — | 
                                                1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                6,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of investment securities | — | 
                                                -2,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of investment securities | — | 
                                                21,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                10,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of shares of subsidiaries resulting in change in scope of consolidation | — | 
                                                -2,509,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -3,366,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -736,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | ||||||
| Proceeds from long-term borrowings | — | 
                                                90,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                50,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of long-term borrowings | — | 
                                                -224,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -258,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of treasury shares | — | 
                                                -76,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid | — | 
                                                -783,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -202,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                2,045,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -601,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Effect of exchange rate change on cash and cash equivalents | — | 
                                                -80,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                12,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                -1,711,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,095,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                7,657,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                9,368,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                9,230,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                8,134,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |