Quarterly Statement Of Cash Flows
| Concept | 2023-01-01 to 2023-12-31 | As at 2023-12-31 | As at 2022-12-31 | 2022-01-01 to 2022-12-31 | As at 2021-12-31 | 
|---|---|---|---|---|---|
| Quarterly statement of cash flows | |||||
| Statement of cash flows | |||||
| Cash flows from operating activities | |||||
| Subtotal | 
                                                2,563,652,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,985,662,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest and dividends received | 
                                                31,225,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                22,991,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Interest paid | 
                                                -49,726,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -22,194,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Income taxes paid | 
                                                -633,339,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,045,097,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) operating activities | 
                                                1,915,190,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,802,252,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from investing activities | |||||
| Purchase of property, plant and equipment | 
                                                -2,881,422,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -1,904,852,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Proceeds from sale of property, plant and equipment | 
                                                7,748,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,745,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Purchase of investment securities | 
                                                -2,221,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -2,022,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Other, net | 
                                                8,201,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -4,173,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | 
                                                -2,897,286,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -2,016,999,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash flows from financing activities | |||||
| Proceeds from long-term borrowings | 
                                                855,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                5,000,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Repayments of long-term borrowings | 
                                                -714,433,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -453,596,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Dividends paid | 
                                                -1,098,920,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                -766,427,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | 
                                                -1,314,445,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,774,124,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Effect of exchange rate change on cash and cash equivalents | 
                                                84,933,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                84,722,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net increase (decrease) in cash and cash equivalents | 
                                                -2,211,608,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                1,644,099,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | — | 
                                                4,022,190,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                6,233,799,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                4,589,699,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             |