XML 212 R196.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Financial Instruments - Summary of Maturity Analysis for Derivative Financial Instruments (Detail) $ in Thousands, $ in Thousands | Dec. 31, 2017 TWD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2016 TWD ($)
--- | --- | --- | ---
Less than 1 month [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Gross settled | $ (40,897) | $ (1,379) | $ (205,559)
1 to 3 months [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Gross settled | (164,400) | (5,547) | (144,919)
3 months to 1 year [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Gross settled | 227,325 | 7,669 | 655,299
Forward exchange contracts [member] | Less than 1 month [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Net settled | (8,820) | (298) | 22,680
Gross settled | 32,148 | 1,085 | (111,528)
Forward exchange contracts [member] | 1 to 3 months [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Net settled |  |  | 13,320
Gross settled | 30,458 | 1,027 | (3,687)
Forward exchange contracts [member] | 3 months to 1 year [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Gross settled | 3,499 | 118 |
Forward exchange contracts [member] | Inflows [member] | Less than 1 month [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Gross settled | 3,711,302 | 125,213 | 5,134,196
Forward exchange contracts [member] | Inflows [member] | 1 to 3 months [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Gross settled | 2,169,093 | 73,181 | 912,213
Forward exchange contracts [member] | Inflows [member] | 3 months to 1 year [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Gross settled | 390,379 | 13,171 |
Forward exchange contracts [member] | Outflows [member] | Less than 1 month [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Gross settled | (3,679,154) | (124,128) | (5,245,724)
Forward exchange contracts [member] | Outflows [member] | 1 to 3 months [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Gross settled | (2,138,635) | (72,154) | (915,900)
Forward exchange contracts [member] | Outflows [member] | 3 months to 1 year [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Gross settled | (386,880) | (13,154) |
Foreign currency option contracts [member] | Less than 1 month [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Net settled |  |  | (344)
Swap contracts [member] | Less than 1 month [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Gross settled | (73,045) | (2,464) | (94,031)
Swap contracts [member] | 1 to 3 months [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Gross settled | (194,858) | (6,574) | (141,232)
Swap contracts [member] | 3 months to 1 year [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Gross settled | 223,826 | 7,551 | 655,299
Swap contracts [member] | Inflows [member] | Less than 1 month [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Gross settled | 12,116,531 | 408,790 | 5,345,159
Swap contracts [member] | Inflows [member] | 1 to 3 months [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Gross settled | 14,434,880 | 487,007 | 17,399,695
Swap contracts [member] | Inflows [member] | 3 months to 1 year [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Gross settled | 36,676,224 | 1,237,389 | 43,537,500
Swap contracts [member] | Outflows [member] | Less than 1 month [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Gross settled | (12,189,576) | (411,254) | (5,439,190)
Swap contracts [member] | Outflows [member] | 1 to 3 months [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Gross settled | (14,629,738) | (493,581) | (17,540,927)
Swap contracts [member] | Outflows [member] | 3 months to 1 year [member] |  |  |
Disclosure of maturity analysis for derivative financial liabilities [line items] |  |  |
Gross settled | $ (36,452,898) | $ (1,229,838) | $ (42,882,201)

X
- Definition The amount of contractual undiscounted cash flows in relation to contractual amounts to be exchanged in a derivative financial instrument for which gross cash flows are exchanged. [Refer: Derivatives [member]] + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Name IFRS -Number 7 -IssueDate 2017-01-01 -Paragraph B11D -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2017-03-01&anchor=para_B11D_d&doctype=Appendix&seq=2 -URIDate 2017-03-09 + Details
Name: | ifrs-full_ContractualAmountsToBeExchangedInDerivativeFinancialInstrumentForWhichGrossCashFlowsAreExchanged
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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_DisclosureOfMaturityAnalysisForDerivativeFinancialLiabilitiesLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of contractual undiscounted cash flows in relation to net amounts for pay-floating (receive-fixed) interest rate swaps for which net cash flows are exchanged. [Refer: Swap contract [member]] + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Name IFRS -Number 7 -IssueDate 2017-01-01 -Paragraph B11D -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2017-03-01&anchor=para_B11D_c&doctype=Appendix&seq=2 -URIDate 2017-03-09 + Details
Name: | ifrs-full_NetAmountsForPayfloatingReceivefixedInterestRateSwapsForWhichNetCashFlowsAreExchanged
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | ifrs-full_MaturityAxis=ifrs-full_NotLaterThanOneMonthMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MaturityAxis=ifrs-full_LaterThanOneMonthAndNotLaterThanThreeMonthsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MaturityAxis=ifrs-full_LaterThanThreeMonthsAndNotLaterThanOneYearMember
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: | asx_CashAndCashEquivalents1Axis=asx_InflowsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | asx_CashAndCashEquivalents1Axis=asx_OutflowsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfFinancialInstrumentsAxis=asx_ForeignCurrencyOptionContractsMember
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: |