XML 53 R153.htm IDEA: XBRL DOCUMENT
v3.20.1

Significant Commitments and Contingencies - Additional Information (Detail) - TWD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Capital commitments [abstract] |  |
Amount guaranteed by Bank of Taiwan | $ 100,800 | $ 97,500

X
- References No definition available. + Details
Name: | ifrs-full_CapitalCommitmentsAbstract
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Bank guarantees. + References No definition available. + Details
Name: | imos_BankGuarantees
Namespace Prefix: | imos_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant