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Income Tax Expense - Reconciliation of Income Tax Expense and Accounting Profit Before Income Tax (Detail) $ in Thousands, $ in Thousands | 12 Months Ended
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Dec. 31, 2023 TWD ($) | Dec. 31, 2023 USD ($) | Dec. 31, 2022 TWD ($) | Dec. 31, 2021 TWD ($)
Reconciliation of income tax expense and accounting profit before income tax [abstract] |  |  |  |
Tax calculated based on profit before tax and statutory tax rate | $ 451,676 |  | $ 804,086 | $ 1,207,605
Effects from adjustments based on regulation | (74,094) |  | (131,873) | (152,618)
Gain on investment in associates | 19,228 |  | 11,923 |
Prior year income tax overestimation | (182,778) |  | (255,935) | (184,284)
Income tax on unappropriated retained earnings | 85,607 |  | 159,744 | 227,467
Effect of different tax rates in countries in which the Group operates | 1,022 |  | 230 | 148
Income tax expense | $ 300,661 | $ 9,819 | $ 588,175 | $ 1,098,318

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- Definition The aggregate amount included in the determination of profit (loss) for the period in respect of current tax and deferred tax. [Refer: Current tax expense (income); Deferred tax expense (income)] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2023-01-01 -Paragraph 23 -Subparagraph h -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2023-en-r&anchor=para_23_h&doctype=Standard -URIDate 2023-03-23 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 26 -IssueDate 2023-01-01 -Paragraph 35 -Subparagraph b -Clause viii -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=26&code=ifrs-tx-2023-en-r&anchor=para_35_b_viii&doctype=Standard -URIDate 2023-03-23 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2023-01-01 -Paragraph 79 -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2023-en-r&anchor=para_79&doctype=Standard -URIDate 2023-03-23 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2023-01-01 -Paragraph 81 -Subparagraph c -Clause i -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2023-en-r&anchor=para_81_c_i&doctype=Standard -URIDate 2023-03-23 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2023-01-01 -Paragraph 81 -Subparagraph c -Clause ii -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2023-en-r&anchor=para_81_c_ii&doctype=Standard -URIDate 2023-03-23 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 12 -IssueDate 2023-01-01 -Paragraph B13 -Subparagraph g -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2023-en-r&anchor=para_B13_g&doctype=Appendix&subtype=B -URIDate 2023-03-23 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2023-01-01 -Paragraph 82 -Subparagraph d -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_82_d&doctype=Standard -URIDate 2023-03-23 + Details
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- Definition The amount that represents the difference between the tax expense (income) and the product of the accounting profit multiplied by the applicable tax rate(s) that relates to foreign tax rates. [Refer: Accounting profit] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2023-01-01 -Paragraph 81 -Subparagraph c -Clause i -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2023-en-r&anchor=para_81_c_i&doctype=Standard -URIDate 2023-03-23 + Details
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- Definition Reconciliation of income tax expense and accounting profit before income tax. + References No definition available. + Details
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