XML 223 R167.htm IDEA: XBRL DOCUMENT
v3.20.1

Profit Before Income Tax - Summary of Employees' Compensation and Remuneration to Directors (Detail) $ in Thousands, $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2019 TWD ($) | Dec. 31, 2019 USD ($) | Dec. 31, 2018 TWD ($)
Analysis Of Income And Expense [line items] |  |  |
Employees' compensation | $ 34,400 | $ 1,150 | $ 45,430
Remuneration to directors | $ 68,803 | $ 2,300 | 34,073
Resolved by the board of directors [member] |  |  |
Analysis Of Income And Expense [line items] |  |  |
Employees' compensation |  |  | 45,430
Remuneration to directors |  |  | 34,070
Recognized in the consolidated financial statements [member] |  |  |
Analysis Of Income And Expense [line items] |  |  |
Employees' compensation |  |  | 45,430
Remuneration to directors |  |  | $ 34,073

X
- Definition Analysis of income and expense. + References No definition available. + Details
Name: | asx_AnalysisOfIncomeAndExpenseLineItems
Namespace Prefix: | asx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Directors remuneration payable. + References No definition available. + Details
Name: | asx_DirectorsRemunerationPayable
Namespace Prefix: | asx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Employees' compensation. + References No definition available. + Details
Name: | asx_EmployeesCompensation
Namespace Prefix: | asx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | ifrs-full_CategoriesOfRelatedPartiesAxis=asx_ResolvedByTheBoardOfDirectorsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CategoriesOfRelatedPartiesAxis=asx_RecognizedInTheConsolidatedFinancialStatementsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |