Retirement Benefit Plans - Summary of Key Assumptions Used for the Actuarial Valuations (Detail) |
Dec. 31, 2025 |
Dec. 31, 2024 |
|---|---|---|
| Bottom of range [member] | ||
| Disclosure of defined benefit plans [line items] | ||
| Discount rates | 1.08% | 0.81% |
| Expected rates of salary increase | 1.00% | 1.00% |
| Top of range [member] | ||
| Disclosure of defined benefit plans [line items] | ||
| Discount rates | 6.15% | 6.50% |
| Expected rates of salary increase | 5.00% | 5.00% |