Related party transactions - Summary Of Related Party Transactions (Detail) - JPY (¥) ¥ in Millions |
12 Months Ended | ||
|---|---|---|---|
Mar. 31, 2025 |
Mar. 31, 2024 |
Mar. 31, 2023 |
|
| Disclosure of transactions between related parties [line items] | |||
| Sales revenues | ¥ 4,042,632 | ¥ 3,799,268 | ¥ 3,544,240 |
| Cost of products sold (purchases) | 12,972,740 | 12,501,811 | 9,951,507 |
| Associates [Member] | |||
| Disclosure of transactions between related parties [line items] | |||
| Sales revenues | 3,420,576 | 3,137,067 | 2,821,963 |
| Cost of products sold (purchases) | 12,889,776 | 12,426,770 | 9,891,804 |
| Joint ventures [Member] | |||
| Disclosure of transactions between related parties [line items] | |||
| Sales revenues | 622,056 | 662,202 | 722,278 |
| Cost of products sold (purchases) | ¥ 82,963 | ¥ 75,042 | ¥ 59,703 |