v3.26.1
Related Parties - Amount of Transactions with Affiliates and Joint Ventures (Detail) - JPY (¥)
¥ in Millions
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Disclosure of transactions between related parties [line items]      
Sales revenue ¥ 644,961 ¥ 717,463 ¥ 959,930
Purchase 2,126,198 2,093,844 2,062,790
Affiliates [member]      
Disclosure of transactions between related parties [line items]      
Sales revenue 162,973 152,256 141,323
Purchase 1,686,392 1,731,349 1,620,755
Joint ventures [member]      
Disclosure of transactions between related parties [line items]      
Sales revenue 481,988 565,207 818,607
Purchase ¥ 439,806 ¥ 362,495 ¥ 442,035