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Contents of Significant Accounts - Non-controlling Interests (Detail) $ in Thousands, $ in Thousands | 12 Months Ended
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Dec. 31, 2024 TWD ($) | Dec. 31, 2024 USD ($) | Dec. 31, 2023 TWD ($) | Dec. 31, 2022 TWD ($)
Equity [abstract] |  |  |  |
Beginning balance | $ 340,859 |  | $ 343,679 | $ 223,181
Impact of retroactive applications | 0 |  | 0 | (66,089)
Adjusted beginning balance | 340,859 |  | 343,679 | 157,092
Net income (loss) | (104,674) | $ (3,192) | 450,184 | 819,960
Other comprehensive income (loss) | 76 |  | (14) | 8
Share-based payment transactions | 1,913 |  | 5,817 | 1,490
Changes in subsidiaries' ownership | (7,910) |  | 456 | (1,339)
Non-controlling interests | 26,349 |  | 4,187 | 5,456
Derecognition of the non-controlling interests | 0 |  | (463,450) | (638,988)
Ending balance | $ 256,613 | $ 7,826 | $ 340,859 | $ 343,679

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- Definition The profit (loss) from continuing and discontinued operations attributable to non-controlling interests. [Refer: Profit (loss); Non-controlling interests] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 12 -IssueDate 2024-01-01 -Paragraph 12 -Subparagraph e -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2024-en-r&anchor=para_12_e&doctype=Standard -URIDate 2024-03-27 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2024-01-01 -Paragraph 81B -Subparagraph a -Clause i -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_81B_a_i&doctype=Standard -URIDate 2024-03-27 + Details
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