Retirement Benefit Plans - Summary of Key Assumptions Used for the Actuarial Valuations (Detail) |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Bottom of range [member] | ||
| Disclosure of defined benefit plans [line items] | ||
| Discount rates | 0.16% | 0.05% |
| Expected rates of salary increase | 1.00% | 1.00% |
| Top of range [member] | ||
| Disclosure of defined benefit plans [line items] | ||
| Discount rates | 4.91% | 5.63% |
| Expected rates of salary increase | 4.06% | 3.96% |