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Employee benefit expenses - Additional Information (Detail) - TWD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Disclosure of defined benefit plans [Line Items] |  |  |
Accrued Employee Compensation | $ 332,080 | $ 338,356 | $ 199,027
Accrued Directors remuneration | $ 16,604 | $ 16,918 | $ 9,951
Defined benefit pension plan [Member] |  |  |
Disclosure of defined benefit plans [Line Items] |  |  |
Employees' compensation distribution rate | 10.00% |  |
Director remuneration rate no more than | 0.50% |  |

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- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table. + References No definition available. + Details
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- Definition Accrued employee compensation liability. + References No definition available. + Details
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- Definition Director remuneration rate. + References No definition available. + Details
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- Definition Directors remuneration accrued. + References No definition available. + Details
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- Definition Employees' compensation distribution plan rate. + References No definition available. + Details
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- Details
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