XML 170 R154.htm IDEA: XBRL DOCUMENT v3.21.1

Bonds Payable - Summary of Bonds Payable (Detail) $ in Millions	Dec. 31, 2020 TWD ($)
Disclosure Of Detailed Information About Bonds Payable [Abstract]
Unsecured domestic bonds	$ 20,000
Less: Discounts on bonds payable	(20)
Bonds payable	$ 19,980

X

- Definition

Disclosure of detailed information about bonds payable.

+ References

No definition available.

+ Details

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

X

- Definition

Discounts on bonds payable.

+ References

No definition available.

+ Details

Name:	cht_DiscountsOnBondsPayable
Namespace Prefix:	cht_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Unsecured domestic bonds.

+ References

No definition available.

+ Details

Name:	cht_UnsecuredDomesticBonds
Namespace Prefix:	cht_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

The amount of bonds issued by the entity.

+ 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_BondsIssued
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant