Financial instruments - Summary of Equity Instruments Measured at Fair Value Through Other Comprehensive Income (Detail) - JPY (¥) ¥ in Millions |
Mar. 31, 2026 |
Mar. 31, 2025 |
|---|---|---|
| Marketable Equity Instruments [Member] | ||
| Disclosure of fair value of investments in equity instruments designated at fair value through other comprehensive income [line items] | ||
| Equity instruments measured at fair value through other comprehensive income | ¥ 148,537 | ¥ 86,339 |
| Non-marketable equity instruments [Member] | ||
| Disclosure of fair value of investments in equity instruments designated at fair value through other comprehensive income [line items] | ||
| Equity instruments measured at fair value through other comprehensive income | 318,952 | 302,488 |
| Equity Instruments [Member] | ||
| Disclosure of fair value of investments in equity instruments designated at fair value through other comprehensive income [line items] | ||
| Equity instruments measured at fair value through other comprehensive income | ¥ 467,489 | ¥ 388,827 |