Retirement Benefit Plans - Summary of Defined Benefit Plans Amounts Included in Consolidated Balance Sheets (Detail) $ in Thousands, $ in Thousands |
Dec. 31, 2025
TWD ($)
|
Dec. 31, 2025
USD ($)
|
Dec. 31, 2024
TWD ($)
|
|---|---|---|---|
| Disclosure of net defined benefit liability (asset) [abstract] | |||
| Present value of the defined benefit obligation | $ 11,431,170 | $ 364,398 | $ 10,123,897 |
| Fair value of the plan assets | (7,819,145) | (249,255) | (7,254,310) |
| Net defined benefit liabilities | 3,612,025 | 115,143 | 2,869,587 |
| Recorded under other payables | (19,057) | (608) | (18,622) |
| Recorded under other non-current assets | 342,046 | 10,904 | 164,176 |
| Recorded under net defined benefit liabilities | $ 3,935,014 | $ 125,439 | $ 3,015,141 |