XML 92 R75.htm IDEA: XBRL DOCUMENT
v3.25.1

Contents of Significant Accounts - Equity - Additional Information (Detail) |  |  | 12 Months Ended
--- | --- | --- | ---
Dec. 05, 2024 shares $ / shares | Dec. 05, 2023 shares $ / shares | Dec. 31, 2024 shares $ / shares | Dec. 31, 2023 shares $ / shares
Disclosure of classes of share capital [line items] |  |  |  |
Shares authorized |  |  | 26,000,000,000 | 26,000,000,000
Shares issued |  |  | 12,560,716,000 | 12,529,822,000
Shares par value | $ / shares |  |  | $ 10 | $ 10
Number of common shares represented by 1 ADS |  |  | 5 |
Percentage of legal reserve |  |  | 10.00% |
Cash dividends | $ / shares |  |  |  | $ 3.00011747
American depositary shares [member] |  |  |  |
Disclosure of classes of share capital [line items] |  |  |  |
Number of American Depositary Shares traded on NYSE |  |  | 115,000,000 | 121,000,000
Number of common shares represented by issued American Depositary Shares |  |  | 576,000,000 | 607,000,000
Bottom of range [member] |  |  |  |
Disclosure of classes of share capital [line items] |  |  |  |
Percentage of cash dividend on dividend distribution |  |  | 20.00% |
Percentage of stock dividend on dividend distribution |  |  | 0.00% |
Top of range [member] |  |  |  |
Disclosure of classes of share capital [line items] |  |  |  |
Percentage of cash dividend on dividend distribution |  |  | 100.00% |
Percentage of stock dividend on dividend distribution |  |  | 80.00% |
Restricted Stocks [member] |  |  |  |
Disclosure of classes of share capital [line items] |  |  |  |
Shares par value | $ / shares | $ 10 | $ 10 |  |
Number of other equity instruments granted in share-based payment arrangement | 33,000,000 | 27,000,000 |  |
Number of other equity instruments recalled and cancelled in share-based payment arrangement |  |  | 2,000,000 | 2,000,000

X
- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table. + References No definition available. + Details
Name: | ifrs-full_DisclosureOfClassesOfShareCapitalLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of dividends paid per ordinary share. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 34 -IssueDate 2024-01-01 -Paragraph 16A -Subparagraph f -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=34&code=ifrs-tx-2024-en-r&anchor=para_16A_f&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_DividendsPaidOrdinarySharesPerShare
Namespace Prefix: | ifrs-full_
Data Type: | dtr-2022:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of other equity instruments (ie other than share options) granted in a share-based payment arrangement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IFRS -Number 2 -IssueDate 2024-01-01 -Paragraph 45 -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2024-en-r&anchor=para_45&doctype=Standard -URIDate 2024-03-27 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 2 -IssueDate 2024-01-01 -Paragraph 47 -Subparagraph b -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2024-en-r&anchor=para_47_b&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_NumberOfInstrumentsOtherEquityInstrumentsGranted
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of shares authorised. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2024-01-01 -Paragraph 79 -Subparagraph a -Clause i -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_79_a_i&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_NumberOfSharesAuthorised
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of shares issued by the entity. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2024-01-01 -Paragraph 106 -Subparagraph d -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_106_d&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_NumberOfSharesIssued
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The nominal value per share. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2024-01-01 -Paragraph 79 -Subparagraph a -Clause iii -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_79_a_iii&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_ParValuePerShare
Namespace Prefix: | ifrs-full_
Data Type: | dtr-2022:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of cash dividend on dividend distribution. + References No definition available. + Details
Name: | umc_CashDividendPercentageOnDividendDistribution
Namespace Prefix: | umc_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of American Depositary Shares issued. + References No definition available. + Details
Name: | umc_NumberOfAmericanDepositarySharesIssued
Namespace Prefix: | umc_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of common shares represented by ADSs. + References No definition available. + Details
Name: | umc_NumberOfCommonSharesRepresentedByADSs
Namespace Prefix: | umc_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of common shares represented by issued American Depositary Shares. + References No definition available. + Details
Name: | umc_NumberOfCommonSharesRepresentedByIssuedAmericanDepositaryShares
Namespace Prefix: | umc_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of other equity instruments (ie other than share options) recalled and cancelled in a share-based payment arrangement. + References No definition available. + Details
Name: | umc_NumberOfOtherEquityInstrumentsRecalledAndCancelledInSharebasedPaymentArrangement
Namespace Prefix: | umc_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of legal reserve. + References No definition available. + Details
Name: | umc_PercentageOfLegalReserve
Namespace Prefix: | umc_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of stock dividend on dividend distribution. + References No definition available. + Details
Name: | umc_StockDividendPercentageOnDividendDistribution
Namespace Prefix: | umc_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_ClassesOfShareCapitalAxis=umc_AmericanDepositarySharesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_BottomOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_TopOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfSharebasedPaymentArrangementsAxis=umc_RestrictedStocksMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |