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 | — | 
                                                1,416,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,264,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | — | 
                                                224,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                176,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | — | 
                                                -118,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -124,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | — | 
                                                -371,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -116,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | — | 
                                                1,151,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | ||||||
| Purchase of property, plant and equipment | — | 
                                                -761,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -664,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of investment securities | — | 
                                                -6,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -13,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of investment securities | — | 
                                                206,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,103,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Loan advances | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from collection of loans receivable | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                11,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | — | 
                                                -52,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -122,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -614,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                314,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | ||||||
| Proceeds from long-term borrowings | — | 
                                                5,200,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                3,400,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of long-term borrowings | — | 
                                                -6,037,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -6,644,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of treasury shares | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                0
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid | — | 
                                                -633,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -557,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                -116,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,396,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Effect of exchange rate change on cash and cash equivalents | — | 
                                                408,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                264,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | — | 
                                                828,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,383,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                5,768,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,939,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                7,329,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                5,730,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |