Contents of Significant Accounts - Summary of Details on Derecognition of Such Investments (Detail) - TWD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Disposed and Derecognized Investments Designated as Fair Value Through Other Comprehensive Income [Abstract] | |||
| Fair value on the date of disposal | $ 0 | $ 0 | $ 3,035,999 |
| Cumulative gains (losses) reclassified to retained earnings due to derecognition | $ 0 | $ 0 | $ (1,628,388) |