XML 198 R88.htm IDEA: XBRL DOCUMENT
v3.20.1

Financial Instruments at Fair Value Through Profit or Loss - Summary of Outstanding Contracts Not Accounted for Hedge Accounting (Detail) € in Thousands, ₩ in Thousands, ¥ in Thousands, ¥ in Thousands, RM in Thousands, $ in Thousands, $ in Thousands, $ in Thousands, $ in Thousands | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2019 TWD ($) | Dec. 31, 2018 TWD ($) | Dec. 31, 2019 USD ($) | Dec. 31, 2019 CNY (¥) | Dec. 31, 2019 SGD ($) | Dec. 31, 2019 JPY (¥) | Dec. 31, 2019 HKD ($) | Dec. 31, 2019 MYR (RM) | Dec. 31, 2019 KRW (₩) | Dec. 31, 2018 USD ($) | Dec. 31, 2018 CNY (¥) | Dec. 31, 2018 SGD ($) | Dec. 31, 2018 JPY (¥) | Dec. 31, 2018 MYR (RM) | Dec. 31, 2018 EUR (€)
Bottom of range [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period |  | 2019-01 |  |  |  |  |  |  |  |  |  |  |  |  |
Swap contracts [member] | Sell NT$/buy US$ [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional Amount | $ 50,241,799 | $ 49,570,469 | $ 1,660,000 |  |  |  |  |  |  | $ 1,687,400 |  |  |  |  |
Swap contracts [member] | Sell NT$/buy US$ [member] | Bottom of range [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-01 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Swap contracts [member] | Sell NT$/buy US$ [member] | Top of range [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-12 | 2018-01 |  |  |  |  |  |  |  |  |  |  |  |  |
Swap contracts [member] | Sell US$/buy CNY [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-02 | 2019-01 |  |  |  |  |  |  |  |  |  |  |  |  |
Notional Amount |  |  | 49,666 | ¥ 349,800 |  |  |  |  |  | 50,292 | ¥ 349,800 |  |  |  |
Swap contracts [member] | Sell US$/buy JPY [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period |  | 2019-01 |  |  |  |  |  |  |  |  |  |  |  |  |
Notional Amount |  |  | 45,878 |  |  | ¥ 5,000,000 |  |  |  | 54,203 |  |  | ¥ 6,090,000 |  |
Swap contracts [member] | Sell US$/buy JPY [member] | Bottom of range [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-02 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Swap contracts [member] | Sell US$/buy JPY [member] | Top of range [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-03 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Swap contracts [member] | Sell US$/buy NT$ [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-01 | 2019-01 |  |  |  |  |  |  |  |  |  |  |  |  |
Notional Amount | $ 5,719,478 | $ 6,423,242 | 189,960 |  |  |  |  |  |  | 208,800 |  |  |  |  |
Swap contracts [member] | Sell US$/Buy KRW [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-01 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional Amount |  |  | 28,000 |  |  |  |  |  | ₩ 32,454,800 |  |  |  |  |  |
Swap contracts [member] | Sell US$/Buy MYR [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-01 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional Amount |  |  | 11,000 |  |  |  |  | RM 45,507 |  |  |  |  |  |  |
Forward exchange contracts [member] | Sell NT$/buy US$ [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-01 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional Amount | $ 2,275,860 | $ 2,453,540 | 75,000 |  |  |  |  |  |  | 80,000 |  |  |  |  |
Forward exchange contracts [member] | Sell NT$/buy US$ [member] | Bottom of range [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period |  | 2019-01 |  |  |  |  |  |  |  |  |  |  |  |  |
Forward exchange contracts [member] | Sell NT$/buy US$ [member] | Top of range [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period |  | 2019-02 |  |  |  |  |  |  |  |  |  |  |  |  |
Forward exchange contracts [member] | Sell US$/buy CNY [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period |  | 2019-01 |  |  |  |  |  |  |  |  |  |  |  |  |
Notional Amount |  |  | 109,000 | 767,277 |  |  |  |  |  | 29,000 | ¥ 200,108 |  |  |  |
Forward exchange contracts [member] | Sell US$/buy CNY [member] | Bottom of range [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-01 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Forward exchange contracts [member] | Sell US$/buy CNY [member] | Top of range [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-03 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Forward exchange contracts [member] | Sell US$/buy JPY [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional Amount |  |  | 87,398 |  |  | ¥ 9,509,491 |  |  |  | 37,733 |  |  | ¥ 4,231,754 |  |
Forward exchange contracts [member] | Sell US$/buy JPY [member] | Bottom of range [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-01 | 2019-01 |  |  |  |  |  |  |  |  |  |  |  |  |
Forward exchange contracts [member] | Sell US$/buy JPY [member] | Top of range [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-04 | 2019-02 |  |  |  |  |  |  |  |  |  |  |  |  |
Forward exchange contracts [member] | Sell US$/buy NT$ [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional Amount | $ 5,142,441 |  | 170,000 |  |  |  |  |  |  |  |  |  |  |  |
Forward exchange contracts [member] | Sell US$/buy NT$ [member] | Bottom of range [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-01 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Forward exchange contracts [member] | Sell US$/buy NT$ [member] | Top of range [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-02 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Forward exchange contracts [member] | Sell HKD/Buy US$ [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-01 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional Amount |  |  | 218,297 |  |  |  | $ 1,705,281 |  |  |  |  |  |  |  |
Forward exchange contracts [member] | Sell US$/Buy EUR [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period |  | 2019-01 |  |  |  |  |  |  |  |  |  |  |  |  |
Notional Amount |  |  |  |  |  |  |  |  |  | 4,103 |  |  |  |  | € 3,600
Forward exchange contracts [member] | Sell US$/Buy MYR [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional Amount |  |  | 26,000 |  |  |  |  | RM 108,330 |  | 14,000 |  |  |  | RM 58,430 |
Forward exchange contracts [member] | Sell US$/Buy MYR [Member] | Bottom of range [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-01 | 2019-01 |  |  |  |  |  |  |  |  |  |  |  |  |
Forward exchange contracts [member] | Sell US$/Buy MYR [Member] | Top of range [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-05 | 2019-02 |  |  |  |  |  |  |  |  |  |  |  |  |
Forward exchange contracts [member] | Sell US$/Buy SGD [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional Amount |  |  | 8,600 |  | $ 11,691 |  |  |  |  | $ 13,400 |  | $ 18,391 |  |  |
Forward exchange contracts [member] | Sell US$/Buy SGD [Member] | Bottom of range [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-01 | 2019-01 |  |  |  |  |  |  |  |  |  |  |  |  |
Forward exchange contracts [member] | Sell US$/Buy SGD [Member] | Top of range [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-02 | 2019-02 |  |  |  |  |  |  |  |  |  |  |  |  |
Forward exchange contracts [member] | Sell CNY/Buy US$ [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notional Amount |  |  | $ 316,896 | ¥ 2,224,491 |  |  |  |  |  |  |  |  |  |  |
Forward exchange contracts [member] | Sell CNY/Buy US$ [Member] | Bottom of range [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-01 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Forward exchange contracts [member] | Sell CNY/Buy US$ [Member] | Top of range [member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Disclosure of detailed information about financial instruments [line items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maturity Period | 2020-02 |  |  |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition Contracts maturity period. + References No definition available. + Details
Name: | asx_ContractsMaturityPeriod
Namespace Prefix: | asx_
Data Type: | xbrli:gYearMonthItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition The nominal or face amount of a financial instrument, used to calculate payments made on that instrument. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2019-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_112_c&doctype=Standard -URIDate 2019-03-27 + Details
Name: | ifrs-full_NotionalAmount
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

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

X
- Details
Name: | ifrs-full_ClassesOfFinancialInstrumentsAxis=ifrs-full_SwapContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfContractsAxis=asx_SellNTToBuyUSMember
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_TypesOfContractsAxis=asx_SellUSToBuyCNYMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfContractsAxis=asx_SellUSToBuyJPYMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfContractsAxis=asx_SellUSToBuyNTMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfContractsAxis=asx_SellUsToBuyKrwMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfContractsAxis=asx_SellUSToBuyMYRMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfFinancialInstrumentsAxis=ifrs-full_ForwardContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfContractsAxis=asx_SellHkdToBuyUsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfContractsAxis=asx_SellUSToBuyEURMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfContractsAxis=asx_SellUSToBuySGDMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfContractsAxis=asx_SellCnyToBuyUsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |