XML 65 R48.htm IDEA: XBRL DOCUMENT
v3.25.1

Contents of Significant Accounts - Details of Investments Accounted for Under the Equity Method (Detail) $ in Thousands, $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2024 TWD ($) | Dec. 31, 2023 TWD ($) | Dec. 31, 2024 USD ($)
Investments in associates and joint ventures [line items] |  |  |
Amount | $ 33,274,869 | $ 32,785,800 | $ 1,014,787
SILICON INTEGRATED SYSTEMS CORP. (SIS) [member] |  |  |
Investments in associates and joint ventures [line items] |  |  |
Amount | $ 1,922,753 | $ 2,373,060 |
Percentage of ownership or voting rights, Associates | 19.02% | 19.02% |
FARADAY TECHNOLOGY CORP. (FARADAY) [member] |  |  |
Investments in associates and joint ventures [line items] |  |  |
Amount | $ 2,484,001 | $ 1,990,073 |
Percentage of ownership or voting rights, Associates | 13.80% | 13.78% |
UNIMICRON TECHNOLOGY CORP. (UNIMICRON) [member] |  |  |
Investments in associates and joint ventures [line items] |  |  |
Amount | $ 13,824,584 | $ 13,644,560 |
Percentage of ownership or voting rights, Associates | 13.01% | 13.05% |
MTIC HOLDINGS PTE. LTD. [member] |  |  |
Investments in associates and joint ventures [line items] |  |  |
Amount | $ 0 | $ 0 |
Percentage of ownership or voting rights, Associates | 45.44% | 45.44% |
UNITECH CAPITAL INC. [member] |  |  |
Investments in associates and joint ventures [line items] |  |  |
Amount | $ 556,610 | $ 625,667 |
Percentage of ownership or voting rights, Associates | 42.00% | 42.00% |
TRIKNIGHT CAPITAL CORPORATION (TRIKNIGHT) [member] |  |  |
Investments in associates and joint ventures [line items] |  |  |
Amount | $ 1,298,112 | $ 2,109,906 |
Percentage of ownership or voting rights, Associates | 40.00% | 40.00% |
HSUN CHIEH CAPITAL CORP. [member] |  |  |
Investments in associates and joint ventures [line items] |  |  |
Amount | $ 266,066 | $ 235,098 |
Percentage of ownership or voting rights, Associates | 40.00% | 40.00% |
PURIUMFIL INC. [member] |  |  |
Investments in associates and joint ventures [line items] |  |  |
Amount | $ 12,340 | $ 11,474 |
Percentage of ownership or voting rights, Associates | 40.00% | 40.00% |
HSUN CHIEH INVESTMENT CO., LTD. (HSUN CHIEH) [member] |  |  |
Investments in associates and joint ventures [line items] |  |  |
Amount | $ 4,723,930 | $ 4,126,878 |
Percentage of ownership or voting rights, Associates | 36.49% | 36.49% |
YANN YUAN INVESTMENT CO., LTD. (YANN YUAN) [member] |  |  |
Investments in associates and joint ventures [line items] |  |  |
Amount | $ 8,044,460 | $ 7,516,327 |
Percentage of ownership or voting rights, Associates | 26.78% | 26.78% |
UNITED LED CORPORATION HONG KONG LIMITED [member] |  |  |
Investments in associates and joint ventures [line items] |  |  |
Amount | $ 101,468 | $ 93,793 |
Percentage of ownership or voting rights, Associates | 25.14% | 25.14% |
VSENSE CO., LTD. [member] |  |  |
Investments in associates and joint ventures [line items] |  |  |
Amount | $ 0 | $ 0 |
Percentage of ownership or voting rights, Associates | 23.98% | 23.98% |
TRANSLINK CAPITAL PARTNERS I, L.P. [member] |  |  |
Investments in associates and joint ventures [line items] |  |  |
Amount | $ 40,545 | $ 58,964 |
Percentage of ownership or voting rights, Associates | 10.38% | 10.38% |

X
- Definition The amount of investments accounted for using the equity method. The equity method is a method of accounting whereby the investment is initially recognised at cost and adjusted thereafter for the post-acquisition change in the investor's share of net assets of the investee. The investor's profit or loss includes its share of the profit or loss of the investee. The investor's other comprehensive income includes its share of the other comprehensive income of the investee. [Refer: At cost [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2024-01-01 -Paragraph 24 -Subparagraph a -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2024-en-r&anchor=para_24_a&doctype=Standard -URIDate 2024-03-27 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 12 -IssueDate 2024-01-01 -Paragraph B16 -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2024-en-r&anchor=para_B16&doctype=Appendix&subtype=B -URIDate 2024-03-27 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2024-01-01 -Paragraph 54 -Subparagraph e -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_54_e&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_InvestmentAccountedForUsingEquityMethod
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The proportion of ownership interest in an associate attributable to the entity. [Refer: Total for all associates [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 27 -IssueDate 2024-01-01 -Paragraph 17 -Subparagraph b -Clause iii -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=27&code=ifrs-tx-2024-en-r&anchor=para_17_b_iii&doctype=Standard -URIDate 2024-03-27 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 27 -IssueDate 2024-01-01 -Paragraph 16 -Subparagraph b -Clause iii -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=27&code=ifrs-tx-2024-en-r&anchor=para_16_b_iii&doctype=Standard -URIDate 2024-03-27 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 12 -IssueDate 2024-01-01 -Paragraph 21 -Subparagraph a -Clause iv -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2024-en-r&anchor=para_21_a_iv&doctype=Standard -URIDate 2024-03-27 + Details
Name: | ifrs-full_ProportionOfOwnershipInterestInAssociate
Namespace Prefix: | ifrs-full_
Data Type: | dtr-2022:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Investments in associates and joint ventures. + References No definition available. + Details
Name: | umc_InvestmentsInAssociatesAndJointVenturesLineItems
Namespace Prefix: | umc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_SignificantInvestmentsInAssociatesAxis=umc_SiliconIntegratedSystemsCorp.SisMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInAssociatesAxis=umc_FaradayTechnologyCorpMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInAssociatesAxis=umc_UnimicronTechnologyCorpMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInAssociatesAxis=umc_MTICHoldingsPteLtdMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInAssociatesAxis=umc_UnitechCapitalIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInAssociatesAxis=umc_TriKnightCapitalCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInAssociatesAxis=umc_HsunChiehCapitalCorpMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInAssociatesAxis=umc_PuriumfilIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInAssociatesAxis=umc_HsunChiehInvestmentCo.LtdMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInAssociatesAxis=umc_YannYuanInvestmentCo.LtdMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInAssociatesAxis=umc_UnitedLEDCorporationHongKongLimitedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInAssociatesAxis=umc_VSenseCoLtdMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInAssociatesAxis=umc_TranslinkCapitalPartnersILPMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |