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Contents of Significant Accounts - Post-Employment Benefits - Additional Information (Detail) - TWD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Disclosure of defined benefit plans and defined contribution plans [Line Items] |  |  |
Actual returns on plan assets | $ 241 | $ 37 |
Expected pension fund contribution in 2025 | $ 490 |  |
Weighted-average durations of defined benefit obligation | 8 years | 6 years |
Defined benefit plan [member] |  |  |
Disclosure of defined benefit plans and defined contribution plans [Line Items] |  |  |
Percentages of employees' total monthly salaries and wages to pension fund | 2.00% | 2.00% | 2.00%
Pension expenses | $ 35 | $ 45 | $ 34
Defined contribution plan [member] |  |  |
Disclosure of defined benefit plans and defined contribution plans [Line Items] |  |  |
Percentage of employees' monthly salary or wages as monthly contributions to defined contribution plan | 6.00% | 6.00% | 6.00%
Pension expenses | $ 1,978 | $ 1,655 | $ 1,880

X
- Definition The estimate of the expected contributions to be made to a defined benefit plan for the next annual reporting period. [Refer: Defined benefit plans [domain]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2024-01-01 -Paragraph 147 -Subparagraph b -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_147_b&doctype=Standard -URIDate 2024-03-27 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2024-01-01 -Paragraph 148 -Subparagraph d -Clause iii -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_148_d_iii&doctype=Standard -URIDate 2024-03-27 + Details
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- Definition The amount of post-employment benefit expense included in profit or loss relating to defined benefit plans. [Refer: Profit (loss); Defined benefit plans [domain]] [Contrast: Increase (decrease) in net defined benefit liability (asset) resulting from expense (income) in profit or loss] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 19 -IssueDate 2024-01-01 -Paragraph 5 -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_5&doctype=Standard -URIDate 2024-03-27 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 19 -IssueDate 2024-01-01 -Paragraph 135 -Subparagraph b -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_135_b&doctype=Standard -URIDate 2024-03-27 + Details
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- Definition The amount of post-employment benefit expense relating to defined contribution plans. Defined contribution plans are post-employment benefit plans under which an entity pays fixed contributions into a separate entity (a fund) and will have no legal or constructive obligation to pay further contributions if the fund does not hold sufficient assets to pay all employee benefits relating to employee service in the current and prior periods. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2024-01-01 -Paragraph 53 -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_53&doctype=Standard -URIDate 2024-03-27 + Details
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- Definition The weighted average duration of a defined benefit obligation. [Refer: Weighted average [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2024-01-01 -Paragraph 147 -Subparagraph c -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_147_c&doctype=Standard -URIDate 2024-03-27 + Details
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- Definition Actual return on plan assets. + References No definition available. + Details
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- Definition Disclosure of defined benefit plans and defined contribution plans [Line Items] + References No definition available. + Details
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