Operating Segment Information - Geographic Non-current Assets Information (Detail) - TWD ($) $ in Thousands |
Dec. 31, 2025 |
Dec. 31, 2024 |
|---|---|---|
| Disclosure of Geographical Areas [Line Items] | ||
| Non-current assets | $ 288,673,833 | $ 300,825,264 |
| Taiwan [member] | ||
| Disclosure of Geographical Areas [Line Items] | ||
| Non-current assets | 121,675,444 | 143,009,330 |
| Singapore [member] | ||
| Disclosure of Geographical Areas [Line Items] | ||
| Non-current assets | 124,957,211 | 107,247,569 |
| China (includes Hong Kong) [member] | ||
| Disclosure of Geographical Areas [Line Items] | ||
| Non-current assets | 31,711,159 | 38,271,386 |
| Japan [member] | ||
| Disclosure of Geographical Areas [Line Items] | ||
| Non-current assets | 10,281,205 | 12,235,336 |
| Others [member] | ||
| Disclosure of Geographical Areas [Line Items] | ||
| Non-current assets | $ 48,814 | $ 61,643 |