Description of option life locked share options granted.

No definition available.

Name:	asx_DescriptionOfOptionLifeLockedShareOptionsGranted
Namespace Prefix:	asx_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

The expected volatility of the share price used to calculate the fair value of the share options granted. Expected volatility is a measure of the amount by which a price is expected to fluctuate during a period. The measure of volatility used in option pricing models is the annualised standard deviation of the continuously compounded rates of return on the share over a period of time.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2021-01-01
-Paragraph 47
-Subparagraph a
-Clause i
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2021-en-r&anchor=para_47_a_i&doctype=Standard
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_DescriptionOfExpectedVolatilityShareOptionsGranted
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The option life of share options granted.

+ References

+ Details

Name:	ifrs-full_DescriptionOfOptionLifeShareOptionsGranted
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

The implied yield currently available on zero-coupon government issues of the country in whose currency the exercise price for share options granted is expressed, with a remaining term equal to the expected term of the option being valued (based on the option's remaining contractual life and taking into account the effects of expected early exercise). [Refer: Government [member]]

+ References

+ Details

Name:	ifrs-full_DescriptionOfRiskFreeInterestRateShareOptionsGranted
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table.

+ References

No definition available.

+ Details

Name:	ifrs-full_DisclosureOfTermsAndConditionsOfSharebasedPaymentArrangementLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The exercise price of share options granted.

+ References

+ Details

Name:	ifrs-full_ExercisePriceShareOptionsGranted2019
Namespace Prefix:	ifrs-full_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average share price used as input to the option pricing model to calculate the fair value of share options granted. [Refer: Option pricing model [member]; Weighted average [member]]

+ References

+ Details

Name:	ifrs-full_WeightedAverageSharePriceShareOptionsGranted2019
Namespace Prefix:	ifrs-full_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	ifrs-full_TypesOfSharebasedPaymentArrangementsAxis=asx_TrinomialTreeModelMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	asx_PlanNameAxis=asx_UsishstockOptionPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	asx_PlanNameAxis=asx_UsishTwoThousandAndTwentyShareOptionsPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_TypesOfSharebasedPaymentArrangementsAxis=asx_BinomialMethodMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	asx_PlanNameAxis=asx_UsishCoreEmployeesStockOwnershipPlanRestrictedSharesAmendedInTwoThousandAndTwentyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	asx_PlanNameAxis=asx_UsishCoreEmployeesStockOwnershipPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	asx_PlanNameAxis=asx_UsishEmployeeStockOwnershipRestrictedStockOwnershipPlanAmendmentTwoThousandAndTwentyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	asx_PlanNameAxis=asx_UsishEmployeesStockOwnershipPlanRestrictedSharesAmendedInTwoThousandAndTwentyOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

Share-based Payment Arrangements - Summary of Fair Value using Trinomial Tree Model and Inputs (Detail)	12 Months Ended
	Dec. 31, 2021 Years ¥ / shares	Dec. 31, 2020 Years yr ¥ / shares	Dec. 31, 2019 yr Years ¥ / shares
Trinomial Tree Model [member] \| USISH stock option plan [Member]
Disclosure of terms and conditions of share-based payment arrangement [Line Items]
Share price at the grant date			¥ 15.84
Exercise price			13.34
Trinomial Tree Model [member] \| USISH two thousand and twenty share options plan [Member]
Disclosure of terms and conditions of share-based payment arrangement [Line Items]
Share price at the grant date		¥ 21.55
Exercise price		21.65
Binomial Method [Member] \| USISH core employees stock ownership plan restricted shares amended in 2020 [Member]
Disclosure of terms and conditions of share-based payment arrangement [Line Items]
Share price at the grant date			16.60
Exercise price			¥ 13.34
Expected volatility			57.21%
Lock-up periods \| Years			1
Risk free interest rate			1.55%
Binomial Method [Member] \| USISH core employees stock ownership plan [Member]
Disclosure of terms and conditions of share-based payment arrangement [Line Items]
Share price at the grant date			¥ 16.30
Exercise price			¥ 13.34
Expected volatility			47.77%
Lock-up periods \| Years			1
Risk free interest rate			2.70%
Binomial Method [Member] \| USISH employee stock ownership restricted stock ownership plan amendment 2020 [Member]
Disclosure of terms and conditions of share-based payment arrangement [Line Items]
Share price at the grant date		¥ 24.30
Expected volatility		56.97%
Lock-up periods \| Years		1.3
Risk free interest rate		2.63%
Binomial Method [Member] \| USISH employee stock ownership restricted stock ownership plan amendment 2021 [Member]
Disclosure of terms and conditions of share-based payment arrangement [Line Items]
Share price at the grant date	¥ 14.65
Expected volatility	47.15%
Lock-up periods \| Years	1.3
Risk free interest rate	2.34%
Bottom of range [member] \| Trinomial Tree Model [member] \| USISH stock option plan [Member]
Disclosure of terms and conditions of share-based payment arrangement [Line Items]
Expected volatility			45.07%
Expected lives \| yr			3
Risk free interest rate			2.80%
Bottom of range [member] \| Trinomial Tree Model [member] \| USISH two thousand and twenty share options plan [Member]
Disclosure of terms and conditions of share-based payment arrangement [Line Items]
Expected volatility		48.14%
Expected lives \| yr		2.2
Risk free interest rate		2.80%
Top of range [member] \| Trinomial Tree Model [member] \| USISH stock option plan [Member]
Disclosure of terms and conditions of share-based payment arrangement [Line Items]
Expected volatility			51.80%
Expected lives \| yr			5
Risk free interest rate			2.97%
Top of range [member] \| Trinomial Tree Model [member] \| USISH two thousand and twenty share options plan [Member]
Disclosure of terms and conditions of share-based payment arrangement [Line Items]
Expected volatility		53.57%
Expected lives \| yr		4.2
Risk free interest rate		2.99%