Revenue from contract with customer.

No definition available.

Name:	cht_RevenueFromContractWithCustomerLineItems
Namespace Prefix:	cht_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of amortisation for assets recognised from the costs incurred to obtain or fulfil contracts with customers. [Refer: Assets recognised from costs to obtain or fulfil contracts with customers; Amortisation expense]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 15
-IssueDate 2022-03-24
-Paragraph 128
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2022-en-r&anchor=para_128_b&doctype=Standard
-URIDate 2022-03-24

+ Details

Name:	ifrs-full_AmortisationAssetsRecognisedFromCostsIncurredToObtainOrFulfilContractsWithCustomers
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The explanation of when the entity expects to recognise the transaction price allocated to the remaining performance obligations as revenue. [Refer: Revenue from contracts with customers; Transaction price allocated to remaining performance obligations]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 15
-IssueDate 2022-03-24
-Paragraph 120
-Subparagraph b
-Clause ii
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2022-en-r&anchor=para_120_b_ii&doctype=Standard
-URIDate 2022-03-24

+ Details

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

- Definition

The amount of the transaction price allocated to the performance obligations that are unsatisfied (or partially unsatisfied) as of the end of the reporting period. The transaction price is the amount of consideration to which an entity expects to be entitled in exchange for transferring promised goods or services to a customer, excluding amounts collected on behalf of third parties (for example, some sales taxes). [Refer: Performance obligations [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 15
-IssueDate 2022-03-24
-Paragraph 120
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=15&code=ifrs-tx-2022-en-r&anchor=para_120_a&doctype=Standard
-URIDate 2022-03-24

+ Details

Name:	ifrs-full_TransactionPriceAllocatedToRemainingPerformanceObligations
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	ifrs-full_ProductsAndServicesAxis=cht_TelecommunicationsBusinessMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_MaturityAxis=ifrs-full_NotLaterThanOneYearMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementScenarioAxis=srt_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_MaturityAxis=ifrs-full_LaterThanOneYearAndNotLaterThanTwoYearsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_MaturityAxis=ifrs-full_LaterThanTwoYearsAndNotLaterThanThreeYearsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ProductsAndServicesAxis=cht_ProjectBusinessMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Revenue - Additional Information (Detail) $ in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2022 TWD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 TWD ($)	Dec. 31, 2020 TWD ($)	Dec. 31, 2025 TWD ($)	Dec. 31, 2024 TWD ($)	Dec. 31, 2023 TWD ($)
Revenue From Contract With Customer [Line Items]
Amortization of incremental costs of obtaining contracts	$ 841	$ 27	$ 815	$ 772
Telecommunications Business [Member]
Revenue From Contract With Customer [Line Items]
Transaction price allocated to performance obligations	$ 31,247
Remaining performance obligations, timing of satisfaction	The Company expects to recognize such revenue of $18,976 million, $9,517 million and $2,754 million in 2023, 2024 and 2025, respectively.	The Company expects to recognize such revenue of $18,976 million, $9,517 million and $2,754 million in 2023, 2024 and 2025, respectively.
Telecommunications Business [Member] \| Year 1 [Member] \| Forecast [Member]
Revenue From Contract With Customer [Line Items]
Transaction price allocated to performance obligations							$ 18,976
Telecommunications Business [Member] \| Later than one year and not later than two years [member] \| Forecast [Member]
Revenue From Contract With Customer [Line Items]
Transaction price allocated to performance obligations						$ 9,517
Telecommunications Business [Member] \| Later than two years and not later than three years [member] \| Forecast [Member]
Revenue From Contract With Customer [Line Items]
Transaction price allocated to performance obligations					$ 2,754
Project Business [Member]
Revenue From Contract With Customer [Line Items]
Transaction price allocated to performance obligations	$ 25,007
Remaining performance obligations, timing of satisfaction	The Company recognizes revenues when the project business contract is completed and accepted by customers. The Company expects to recognize such revenue of $9,374 million, $6,447 million and $9,186 million in 2023, 2024 and 2025, respectively	The Company recognizes revenues when the project business contract is completed and accepted by customers. The Company expects to recognize such revenue of $9,374 million, $6,447 million and $9,186 million in 2023, 2024 and 2025, respectively
Project Business [Member] \| Year 1 [Member] \| Forecast [Member]
Revenue From Contract With Customer [Line Items]
Transaction price allocated to performance obligations							$ 9,374
Project Business [Member] \| Later than one year and not later than two years [member] \| Forecast [Member]
Revenue From Contract With Customer [Line Items]
Transaction price allocated to performance obligations						$ 6,447
Project Business [Member] \| Later than two years and not later than three years [member] \| Forecast [Member]
Revenue From Contract With Customer [Line Items]
Transaction price allocated to performance obligations					$ 9,186