XML 98 R81.htm IDEA: XBRL DOCUMENT
v3.25.1

Contents Of Significant Accounts - Summary of Assumptions Used for Compensation Cost for These Market Conditions Was Measured at Fair Value Initially by Using Monte Carlo Simulation on The Grant Date (Detail) - Two Thousand Twenty Four Plan [Member] - First Tranche [Member] - Restricted Stock Plan For Employees [Member] | 12 Months Ended
--- | ---
Dec. 31, 2024 yr $ / shares
Contents Of Significant Accounts [Line Items] |
Share price of measurement date (NT$/ per share) | $ / shares | $ 44.6
Top of range [member] |
Contents Of Significant Accounts [Line Items] |
Expected volatility | 34.32%
Expected life | 4
Risk-free interest rate | 1.46%
Bottom of range [member] |
Contents Of Significant Accounts [Line Items] |
Expected volatility | 23.76%
Expected life | 2
Risk-free interest rate | 1.40%

X
- Definition Contents of significant accounts. + References No definition available. + Details
Name: | umc_ContentsOfSignificantAccountsLineItems
Namespace Prefix: | umc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The expected life used to calculate the fair value of the share-based payment. + References No definition available. + Details
Name: | umc_ExpectedLifeUsedToCalculateFairValueOfShareBasedPayment
Namespace Prefix: | umc_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | duration

X
- Definition The expected volatility used to calculate the fair value of the share-based payment. + References No definition available. + Details
Name: | umc_ExpectedVolatilityUsedToCalculateFairValueOfShareBasedPayment
Namespace Prefix: | umc_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The risk-free interest rate used to calculate the fair value of the share-based payment. + References No definition available. + Details
Name: | umc_RiskFreeInterestRateUsedToCalculateFairValueOfShareBasedPayment
Namespace Prefix: | umc_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The share price of measurement date used to calculate the fair value of the share-based payment. + References No definition available. + Details
Name: | umc_SharePriceOfMeasurementDateUsedToCalculateFairValueOfShareBasedPayment
Namespace Prefix: | umc_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | umc_PlanAxis=umc_TwoThousandTwentyFourPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | umc_TrancheAxis=umc_FirstTrancheMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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