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Financial Risk Management And Fair Values Of Financial Instruments - Summary of Effect of Profit or Loss or of Other Comprehensive Income from Financial Assets Categorized (Detail) - Financial instruments at fair value through other comprehensive income [member] - TWD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2024 | Dec. 31, 2023
Disclosure of significant unobservable inputs used in fair value measurement of equity [line items] |  |
Favorable Changes | $ 2,714 | $ 2,231
Unfavorable Changes In Fair Value | 2,783 | 2,152
Discount for lack of marketability [member] |  |
Disclosure of significant unobservable inputs used in fair value measurement of equity [line items] |  |
Favorable Changes | 1,208 | 1,453
Unfavorable Changes In Fair Value | 1,233 | 1,413
Foreign unlisted stocks [member] | Price to book ratio multiple [member] |  |
Disclosure of significant unobservable inputs used in fair value measurement of equity [line items] |  |
Favorable Changes | 1,392 | 30
Unfavorable Changes In Fair Value | 1,436 | 30
Foreign unlisted stocks [member] | Enter prise value EBITDA multiple [member] |  |
Disclosure of significant unobservable inputs used in fair value measurement of equity [line items] |  |
Favorable Changes | 114 | 748
Unfavorable Changes In Fair Value | $ 114 | $ 709

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