XML 175 R116.htm IDEA: XBRL DOCUMENT
v3.20.1

Lease Arrangements - Summary of the Group's Lease Liabilities are Mainly From Land and Buildings and Improvements. Range of Discount Rate for Lease Liabilities (Detail) | Dec. 31, 2019
--- | ---
Land [member] | Bottom of range [member] |
Disclosure of detailed information about property, plant and equipment [line items] |
Discount Rate For Lease Liabilities | 0.54%
Land [member] | Top of range [member] |
Disclosure of detailed information about property, plant and equipment [line items] |
Discount Rate For Lease Liabilities | 4.90%
Buildings and improvements [member] | Bottom of range [member] |
Disclosure of detailed information about property, plant and equipment [line items] |
Discount Rate For Lease Liabilities | 0.30%
Buildings and improvements [member] | Top of range [member] |
Disclosure of detailed information about property, plant and equipment [line items] |
Discount Rate For Lease Liabilities | 8.62%

X
- Definition Discount rate for lease liabilities. + References No definition available. + Details
Name: | asx_DiscountRateForLeaseLiabilities
Namespace Prefix: | asx_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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

X
- Details
Name: | ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ifrs-full_LandMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_BottomOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_TopOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=asx_BuildingsAndImprovementsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |