XML 182 R159.htm IDEA: XBRL DOCUMENT
v3.21.1

Pledged assets - Certain Assets Provided as Collateral Mainly for Long-term Bank Loans and Leases (Detail) - TWD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2020 | Dec. 31, 2019
Statement [LineItems] |  |
Purpose | Lease and bank loan |
Non-current financial assets at amortized cost | $ 48,319 | $ 68,450
Assets pledged as collateral for liabilities | $ 11,505,888 | 8,723,029
Land [member] |  |
Statement [LineItems] |  |
Purpose | Bank loan |
Property, plant and equipment, net | $ 452,738 | 452,738
Buildings [member] |  |
Statement [LineItems] |  |
Purpose | Bank loan |
Property, plant and equipment, net | $ 4,092,287 | 4,095,929
Machinery and equipment [member] |  |
Statement [LineItems] |  |
Purpose | Bank loan |
Property, plant and equipment, net | $ 6,912,544 | $ 4,105,912

X
- Definition The fair value of collateral held that is permitted to be sold or repledged in the absence of default by the owner of the collateral. [Refer: At fair value [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2020-01-01 -Paragraph 15 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2020-en-r&anchor=para_15_a&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_AssetsHeldAsCollateralPermittedToBeSoldOrRepledgedAtFairValue
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- Definition The amount of property, plant and equipment pledged as security for liabilities. [Refer: Property, plant and equipment] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 74 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_74_a&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_PropertyPlantAndEquipmentPledgedAsSecurity
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- Definition Description of borrowings purpose. + References No definition available. + Details
Name: | imos_DescriptionOfBorrowingsPurpose
Namespace Prefix: | imos_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Definition Non-current pledged collateral assets at amortised cost. + References No definition available. + Details
Name: | imos_NoncurrentPledgedCollateralAssetsAtAmortisedCost
Namespace Prefix: | imos_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

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- Details
Name: | ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ifrs-full_LandMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
Name: | ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ifrs-full_BuildingsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
Name: | ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=imos_MachineryAndEquipment1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |