Supplemental cash flow information - Summary of Interest and Dividends (Detail) - JPY (¥) ¥ in Millions |
12 Months Ended | ||
|---|---|---|---|
Mar. 31, 2025 |
Mar. 31, 2024 |
Mar. 31, 2023 |
|
| Interest Received [Abstract] | |||
| Financial services revenue | ¥ 260,725 | ¥ 244,292 | ¥ 224,137 |
| Financial income | 49,582 | 36,295 | 20,872 |
| Dividends Received [Abstract] | |||
| Financial services revenue | 41,214 | 52,760 | 23,409 |
| Financial income | 1,390 | 1,138 | 3,488 |
| Interest Paid [Abstract] | |||
| Financial services expenses | 91,431 | 74,857 | 27,352 |
| Financial expenses | ¥ 21,829 | ¥ 22,667 | ¥ 11,663 |