v3.26.1
Intangible Assets - Schedule of Reconciliation of Changes in Intangible Assets (Details) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Reconciliation of changes in intangible assets and goodwill [abstract]      
Beginning balance ¥ 3,631,560 ¥ 4,274,682  
Amortization (633,544) (643,233) ¥ (652,117)
Impairment losses (133,402) (95,602) (169,405)
Ending balance 3,419,348 3,631,560 4,274,682
Software      
Reconciliation of changes in intangible assets and goodwill [abstract]      
Beginning balance 144,547 149,632  
Ending balance 149,287 144,547 149,632
Intangible assets associated with products      
Reconciliation of changes in intangible assets and goodwill [abstract]      
Beginning balance 3,475,773 4,113,726  
Ending balance 3,258,905 3,475,773 4,113,726
Other      
Reconciliation of changes in intangible assets and goodwill [abstract]      
Beginning balance 11,240 11,324  
Ending balance 11,156 11,240 11,324
Acquisition cost      
Reconciliation of changes in intangible assets and goodwill [abstract]      
Beginning balance 8,538,208 8,601,492  
Additions and other increases 226,845 94,248  
Disposals and other decreases (32,238) (19,617)  
Reclassification to assets held for sale (Note 18) (46,943) (11,204)  
Foreign currency translation differences 672,419 (126,712)  
Ending balance 9,358,291 8,538,208 8,601,492
Acquisition cost | Software      
Reconciliation of changes in intangible assets and goodwill [abstract]      
Beginning balance 319,318 289,116  
Additions and other increases 35,420 38,769  
Disposals and other decreases (15,002) (4,048)  
Reclassification to assets held for sale (Note 18) 0 (95)  
Foreign currency translation differences 32,307 (4,424)  
Ending balance 372,043 319,318 289,116
Acquisition cost | Intangible assets associated with products      
Reconciliation of changes in intangible assets and goodwill [abstract]      
Beginning balance 8,206,937 8,300,433  
Additions and other increases 191,426 55,345  
Disposals and other decreases (17,213) (15,453)  
Reclassification to assets held for sale (Note 18) (46,943) (11,108)  
Foreign currency translation differences 640,053 (122,279)  
Ending balance 8,974,261 8,206,937 8,300,433
Acquisition cost | Other      
Reconciliation of changes in intangible assets and goodwill [abstract]      
Beginning balance 11,953 11,944  
Additions and other increases 0 134  
Disposals and other decreases (24) (116)  
Reclassification to assets held for sale (Note 18) 0 0  
Foreign currency translation differences 59 (9)  
Ending balance 11,988 11,953 11,944
Accumulated depreciation and accumulated impairment losses      
Reconciliation of changes in intangible assets and goodwill [abstract]      
Beginning balance (4,906,647) (4,326,810)  
Amortization (547,116) (589,187)  
Impairment losses (133,402) (95,602)  
Disposals and other decreases 32,202 18,384  
Reclassification to assets held for sale (Note 18) 43,353 11,171  
Foreign currency translation differences (427,332) 75,397  
Ending balance (5,938,943) (4,906,647) (4,326,810)
Accumulated depreciation and accumulated impairment losses | Software      
Reconciliation of changes in intangible assets and goodwill [abstract]      
Beginning balance (174,771) (139,483)  
Amortization (42,544) (40,414)  
Impairment losses (762) (556)  
Disposals and other decreases 14,987 3,081  
Reclassification to assets held for sale (Note 18) 0 63  
Foreign currency translation differences (19,665) 2,538  
Ending balance (222,756) (174,771) (139,483)
Accumulated depreciation and accumulated impairment losses | Intangible assets associated with products      
Reconciliation of changes in intangible assets and goodwill [abstract]      
Beginning balance (4,731,164) (4,186,707)  
Amortization (504,475) (548,660)  
Impairment losses (132,640) (95,047)  
Disposals and other decreases 17,213 15,283  
Reclassification to assets held for sale (Note 18) 43,353 11,108  
Foreign currency translation differences (407,643) 72,858  
Ending balance (5,715,356) (4,731,164) (4,186,707)
Accumulated depreciation and accumulated impairment losses | Other      
Reconciliation of changes in intangible assets and goodwill [abstract]      
Beginning balance (713) (620)  
Amortization (97) (113)  
Impairment losses 0 0  
Disposals and other decreases 2 20  
Reclassification to assets held for sale (Note 18) 0 0  
Foreign currency translation differences (25) 1  
Ending balance ¥ (832) ¥ (713) ¥ (620)