XML 122 R160.htm IDEA: XBRL DOCUMENT
v3.20.1

Related Party Transactions - Additional Information (Detail) $ in Thousands, $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2018 TWD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2017 TWD ($)
Disclosure of transactions between related parties [Line Items] |  |  |
Acquisition of investment in associate | $ 794,694 |  | $ 1,373,486
ChipMOS BVI and Unimos Shanghai [member] |  |  |
Disclosure of transactions between related parties [Line Items] |  |  |
Acquisition of investment in associate | $ 794,694 | $ 25,962 | $ 1,373,486

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

X
- Definition The cash outflow for the purchase of interests in associates. [Refer: Associates [member]] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 7 -IssueDate 2019-01-01 -Paragraph 16 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2019-en-r&anchor=para_16&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_PurchaseOfInterestsInAssociates
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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