XML 98 R79.htm IDEA: XBRL DOCUMENT v3.21.1

Summary of Significant Accounting Policies - Additional Information (Detail)	Dec. 31, 2020 TWD-USD shares	Dec. 31, 2019 shares
Disclosure of subsidiaries [line items]
Convenience exchange rate | TWD-USD	28.08
Number of shares in entity held by entity	72,941,000	72,941,000
Bottom of range [member]
Disclosure of subsidiaries [line items]
Number of shares in entity held by entity	1
Percentage of total shares held in Subsidiaries	0.10%

X

- Definition

Percentage of total shares held in Subsidiaries.

+ References

No definition available.

+ Details

Name:	asx_PercentageOfTotalSharesHeldInSubsidiaries
Namespace Prefix:	asx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The spot exchange rate at the end of the reporting period. Exchange rate is the ratio of exchange for two currencies. Spot exchange rate is the exchange rate for immediate delivery.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 112
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_ClosingForeignExchangeRate
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:decimalItemType
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_DisclosureOfSignificantInvestmentsInSubsidiariesLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The number of shares in the entity held by the entity or by its subsidiaries or associates. [Refer: Associates [member]; Subsidiaries [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 79
-Subparagraph a
-Clause vi
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_79_a_vi&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_SharesInEntityHeldByEntityOrByItsSubsidiariesOrAssociates
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

X

- Details

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