XML 39 R78.htm IDEA: XBRL DOCUMENT
v3.20.1

Share-based payments (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2019
Text block [abstract] |
Issuance of Restricted Shares | The record dates for the shares issuance were July 21, 2015 and May 10, 2016. The relevant information is as follows:
Type of arrangement |  | Grant date |  | Share price on grant date (in NT$) |  |  | Number of shares (in thousands) |  |  | Number of shares returned due to employee resignation (in thousands) |  |  | Contract period |  |  | Vesting condition
|  |  |  |  |  |  |  |  |  | 2018 |  |  | 2019 |  |  |  |  |  |
Restricted shares award agreement |  | July 21, 2015 |  |  | 36.1 |  |  |  | 15,752 |  |  |  | (256 | ) |  |  | — |  |  |  | 3 years |  |  | Meet service and performance conditions
Restricted shares award agreement |  | May 10, 2016 |  |  | 30.6 |  |  |  | 1,548 |  |  |  | (116 | ) |  |  | (25 | ) |  |  | 3 years |  |  | Meet service and performance conditions

X
- Definition Disclosure of Detailed Information About In Share Based Payment Other Than Equity Instrument Explanatory. + References No definition available. + Details
Name: | imos_DisclosureOfDetailedInformationAboutInShareBasedPaymentOtherThanEquityInstrumentExplanatoryTableTextBlock
Namespace Prefix: | imos_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Text block [abstract] + References No definition available. + Details
Name: | imos_TextBlockAbstract
Namespace Prefix: | imos_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration