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v3.21.1

Capital Surplus - Details of Capital Surplus (Detail) $ in Thousands, $ in Thousands |  | 12 Months Ended
--- | --- | ---
Mar. 07, 2019 TWD ($) | Dec. 31, 2020 TWD ($) | Dec. 31, 2020 USD ($) | Dec. 31, 2019 TWD ($) | Dec. 31, 2018 TWD ($)
Statement [LineItems] |  |  |  |  |
Beginning balance |  | $ 6,050,787 |  |  |
Share-based payments |  |  |  | $ 822 | $ 41,043
Capital reduction |  |  |  |  | (1,284,223)
Cancellation of treasury stock | $ 962,503 |  |  |  |
Ending balance |  | 6,050,787 | $ 215,484 | 6,050,787 |
Capital surplus [member] |  |  |  |  |
Statement [LineItems] |  |  |  |  |
Beginning balance |  | 6,050,787 |  | 6,263,553 | 6,271,448
Share-based payments |  |  |  | (412) | (7,967)
Capital reduction |  |  |  |  | 72
Cancellation of treasury stock |  |  |  | (212,354) |
Ending balance |  | 6,050,787 |  | 6,050,787 | 6,263,553
Share premium [member] | Capital surplus [member] |  |  |  |  |
Statement [LineItems] |  |  |  |  |
Beginning balance |  | 5,674,242 |  | 5,873,743 | 5,873,743
Cancellation of treasury stock |  |  |  | (199,501) |
Reclassifications |  | 369,241 |  |  |
Ending balance |  | 6,043,483 |  | 5,674,242 | 5,873,743
Employee restricted shares [member] | Capital surplus [member] |  |  |  |  |
Statement [LineItems] |  |  |  |  |
Beginning balance |  | 369,241 |  | 382,506 | 390,401
Share-based payments |  |  |  | (412) | (7,967)
Capital reduction |  |  |  |  | 72
Cancellation of treasury stock |  |  |  | (12,853) |
Reclassifications |  | (369,241) |  |  |
Ending balance |  |  |  | 369,241 | 382,506
Others [member] | Capital surplus [member] |  |  |  |  |
Statement [LineItems] |  |  |  |  |
Beginning balance |  | 7,304 |  | 7,304 | 7,304
Ending balance |  | $ 7,304 |  | $ 7,304 | $ 7,304

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- Definition The amount received or receivable from the issuance of the entity's shares in excess of nominal value and amounts received from other transactions involving the entity's stock or stockholders. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 55 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_55&doctype=Standard -URIDate 2020-01-01 + Details
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- Definition The amount of treasury stock cancelled during the period. [Refer: Treasury shares] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 106 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_106_d&doctype=Standard -URIDate 2020-01-01 + Details
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- Definition The decrease in equity resulting from a reduction in issued capital. [Refer: Issued capital] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 106 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_106_d&doctype=Standard -URIDate 2020-01-01 + Details
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- Definition Additional paid in capital reclassification. + References No definition available. + Details
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- Definition Increase (decrease) through issuance of restricted shares, equity. + References No definition available. + Details
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