XML 235 R219.htm IDEA: XBRL DOCUMENT v3.22.1

Financial Instruments - Additional Information (Detail) - TWD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Foreign currency risk [Member]
Disclosure of detailed information about financial instruments [Line Items]
Sensitivity rate	5.00%	5.00%	5.00%
Interest rate risk [member]
Disclosure of detailed information about financial instruments [Line Items]
Sensitivity rate	0.25%	0.25%	0.25%
Increase decrease in pre-tax income due to sensitivity analysis	$ 31	$ 19	$ 15
Equity price risk [Member]
Disclosure of detailed information about financial instruments [Line Items]
Sensitivity rate	5.00%	5.00%	5.00%
Equity price risk [Member] | Pre-tax profit [Member]
Disclosure of detailed information about financial instruments [Line Items]
Increase decrease in pretax income of financial assets at FVTPL, FVOCI	$ 46	$ 34	$ 39
Equity price risk [Member] | Pre-tax other comprehensive income [Member]
Disclosure of detailed information about financial instruments [Line Items]
Increase decrease in pretax income of financial assets at FVTPL, FVOCI	$ 181	$ 360	$ 358

X

- Definition

Increase decrease pre-tax profit and pre-tax other comprehensive income of financial assets at FVTOCI.

+ References

No definition available.

+ Details

Name:	cht_IncreaseDecreasePreTaxProfitAndPreTaxOtherComprehensiveIncomeOfFinancialAssetsAtFVTOCI
Namespace Prefix:	cht_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Risk exposure associated with instruments sharing characteristic, percentage change in risk.

+ References

No definition available.

+ Details

Name:	cht_RiskExposureAssociatedWithInstrumentsSharingCharacteristicPercentageChangeInRisk
Namespace Prefix:	cht_
Data Type:	dtr-types: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 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 amount of risk exposure associated with financial instruments with a shared characteristic that identifies a concentration of risks. [Refer: Financial instruments, class [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2021-01-01
-Paragraph B8
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_B8_c&doctype=Appendix&subtype=B
-URIDate 2021-03-24

+ Details

Name:	ifrs-full_RiskExposureAssociatedWithInstrumentsSharingCharacteristic
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

X

- Details

Name:	ifrs-full_TypesOfRisksAxis=ifrs-full_CurrencyRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_TypesOfRisksAxis=ifrs-full_InterestRateRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_TypesOfRisksAxis=ifrs-full_EquityPriceRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_InvestmentsInEquityInstrumentsMeasuredAtFairValueThroughOtherComprehensiveIncomeAxis=cht_PreTaxProfitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_InvestmentsInEquityInstrumentsMeasuredAtFairValueThroughOtherComprehensiveIncomeAxis=cht_PreTaxOtherComprehensiveIncomeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: