Employee Benefits - Summary of Sensitivity Analysis For Actuarial Assumptions Defined Benefit Obligations (Detail) - Actuarial assumption of discount rates [Member] - JPY (¥) ¥ in Millions |
Mar. 31, 2026 |
Mar. 31, 2025 |
|---|---|---|
| Japanese plans [Member] | ||
| Disclosure of sensitivity analysis for actuarial assumptions [line items] | ||
| 0.5% decrease | ¥ 88,346 | ¥ 119,138 |
| 0.5% increase | (80,862) | (103,296) |
| Foreign plans [Member] | ||
| Disclosure of sensitivity analysis for actuarial assumptions [line items] | ||
| 0.5% decrease | 120,176 | 113,268 |
| 0.5% increase | ¥ (118,461) | ¥ (110,060) |