Contents of Significant Accounts - Movement of Loss Allowance (Detail) - Accounts receivable [member] - TWD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Disclosure of financial assets [line items] | ||
| Beginning balance | $ 10,996 | $ 79,062 |
| Net recognition (reversal) for the period | (2,651) | (68,066) |
| Ending balance | $ 8,345 | $ 10,996 |