Shareholdings
| Concept | As at 2024-12-31 | As at 2024-12-31 | As at 2024-12-31 | As at 2023-12-31 | As at 2023-12-31 | As at 2023-12-31 | 
|---|---|---|---|---|---|---|
| Shareholdings | ||||||
| Reporting company | ||||||
| Details of specified investment shares held for purposes other than pure investment | ||||||
| Issue | 
                                                松竹㈱
                                                
                                             | 
                                                小野薬品工業㈱
                                                
                                             | 
                                                東洋製罐グループホールディングス㈱
                                                
                                             | — | — | — | 
| Number of shares | 
                                                142,400
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                1,176,500
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                400,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                400,000
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                1,176,500
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
                                                142,400
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
| Carrying amount | 
                                                1,563,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,922,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                962,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                914,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,960,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,356,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Purpose of shareholding, overview of business alliance, quantitative effects of shareholding and reason for increase in number of shares | 
                                                議決権を持つ株式の所有を通じて、営業活動上の影響を維持・強化するため、保有しております。
                                                
                                             | 
                                                議決権を持つ株式の所有を通じて、営業活動上の影響を維持・強化するため、保有しております。
                                                
                                             | 
                                                議決権を持つ株式の所有を通じて、営業活動上の影響を維持・強化するため、保有しております。
                                                
                                             | — | — | — | 
| Whether issuer of aforementioned shares holds reporting company's shares | 
                                                有
                                                
                                             | 
                                                有
                                                
                                             | 
                                                有
                                                
                                             | — | — | — |