The amount of current lease liabilities. [Refer: Lease liabilities]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 16
-IssueDate 2019-01-01
-Paragraph 47
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=16&code=ifrs-tx-2019-en-r&anchor=para_47_b&doctype=Standard
-URIDate 2019-03-27

+ Details

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

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

- Definition

The amount of liabilities related to the entity's leases. Lease is a contract, or part of a contract, that conveys the right to use an underlying asset for a period of time in exchange for consideration.

+ References

+ Details

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

- Definition

The amount of non-current lease liabilities. [Refer: Lease liabilities]

+ References

+ Details

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

- Details

Name:	ifrs-full_SignificantInvestmentsInAssociatesAxis=cht_ST2SatelliteVenturesPteLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Related Parties Transactions - Summary of Lease Liabilities (Detail) $ in Millions, $ in Millions	Dec. 31, 2019 TWD ($)	Dec. 31, 2019 USD ($)	Jan. 01, 2019 TWD ($)	Dec. 31, 2018 TWD ($)
Disclosure of transactions between related parties [Line Items]
Lease liabilities - current	$ 3,291	$ 110	$ 3,394	$ 0
Lease liabilities - noncurrent	6,467	$ 216	6,946	$ 0
Lease liabilities	9,758		$ 10,340
ST-2 Satellite Ventures Pte., Ltd. ("STS") [Member]
Disclosure of transactions between related parties [Line Items]
Lease liabilities - current	188
Lease liabilities - noncurrent	1,024
Lease liabilities	$ 1,212