XML 89 R73.htm IDEA: XBRL DOCUMENT
v3.24.1.u1

Contents of Significant Accounts - Summary of Stock Held by Associates (Detail) - shares shares in Thousands | Dec. 31, 2023 | Dec. 31, 2022
--- | --- | ---
Disclosure Of Stock Held By Associates [Line Items] |  |  |
Number of shares in entity held by its subsidiaries or associates |  | 900,961 | 634,334
HSUN CHIEH [member] |  |  |
Disclosure Of Stock Held By Associates [Line Items] |  |  |
Number of shares in entity held by its subsidiaries or associates |  | 441,371 | 441,371
YANN YUAN [member] |  |  |
Disclosure Of Stock Held By Associates [Line Items] |  |  |
Number of shares in entity held by its subsidiaries or associates |  | 192,963 | 192,963
SUBTRON, the subsidiary of UNIMICRON [member] |  |  |
Disclosure Of Stock Held By Associates [Line Items] |  |  |
Number of shares in entity held by its subsidiaries or associates | [1] | 47 | 0
SIS [member] |  |  |
Disclosure Of Stock Held By Associates [Line Items] |  |  |
Number of shares in entity held by its subsidiaries or associates | [2] | 266,580 | 0
[1] | Beginning from January 2023, SUBTRON becomes an associate of the Company.
[2] | Beginning from August 2023, SIS becomes an associate of the Company.

X
- Definition The number of shares in the entity held by the entity or by its subsidiaries or associates. [Refer: Associates [member]; Subsidiaries [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2023-01-01 -Paragraph 79 -Subparagraph a -Clause vi -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_79_a_vi&doctype=Standard -URIDate 2023-03-23 + Details
Name: | ifrs-full_SharesInEntityHeldByEntityOrByItsSubsidiariesOrAssociates
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Disclosure of stock held by associates. + References No definition available. + Details
Name: | umc_DisclosureOfStockHeldByAssociatesLineItems
Namespace Prefix: | umc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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_TheSubsidiaryOfUnimicronMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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