Employee benefits - Summary of Sensitivity of the Defined Benefit Obligations (Detail) - Actuarial assumption of discount rates [member] - JPY (¥) ¥ in Millions |
Mar. 31, 2026 |
Mar. 31, 2025 |
|---|---|---|
| Japanese Defined Benefit Plans [Member] | ||
| Disclosure of sensitivity analysis for actuarial assumptions [line items] | ||
| Decrease in significant weighted-average | ¥ 8,434 | ¥ 11,336 |
| Increase in significant weighted-average | (8,113) | (10,878) |
| Foreign Defined Benefit Plan [Member] | ||
| Disclosure of sensitivity analysis for actuarial assumptions [line items] | ||
| Decrease in significant weighted-average | 6,616 | 3,628 |
| Increase in significant weighted-average | ¥ (6,274) | ¥ (3,437) |