XML 203 R184.htm IDEA: XBRL DOCUMENT
v3.19.1

Share-based Payment Arrangements - Summary of Information About New Shares Reserved for Subscription by Employees under Cash Capital Increase Option Plans (Detail) - New shares reserved for subscription by employees under cash capital increase [member] shares in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2017 TWD ($) shares
Disclosure of terms and conditions of share-based payment arrangement [Line Items] |
Number of options, granted | 30,000
Number of options, exercised | 25,164
Fair value of options granted (NT$ per share) | $ | $ 2.80

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_DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of share options exercised in a share-based payment arrangement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 2 -IssueDate 2018-01-01 -Paragraph 45 -Subparagraph b -Clause iv -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_b_iv&doctype=Standard -URIDate 2018-03-16 + Details
Name: | ifrs-full_NumberOfShareOptionsExercisedInSharebasedPaymentArrangement
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of share options granted in a share-based payment arrangement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 2 -IssueDate 2018-01-01 -Paragraph 45 -Subparagraph b -Clause ii -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_b_ii&doctype=Standard -URIDate 2018-03-16 + Details
Name: | ifrs-full_NumberOfShareOptionsGrantedInSharebasedPaymentArrangement
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | duration

X
- Definition The weighted average fair value of share options granted during the period at the measurement date. [Refer: Weighted average [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 2 -IssueDate 2018-01-01 -Paragraph 47 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_47_a&doctype=Standard -URIDate 2018-03-16 + Details
Name: | ifrs-full_WeightedAverageFairValueAtMeasurementDateShareOptionsGranted
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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