XML 225 R209.htm IDEA: XBRL DOCUMENT v3.21.1

Share-based Payments Arrangement - CHTSC's Employee Stock Options Outstanding (Detail) - CHT Security Co., Ltd. (CHTSC) [Member]	12 Months Ended
	Dec. 31, 2020 $ / shares	Dec. 31, 2019 $ / shares	Dec. 20, 2019 $ / shares
Disclosure Of Range Of Exercise Prices Of Outstanding Share Options [Line Items]
Range of Exercise Price	$ 19.085	$ 19.085
Number of Options Outstanding	4,328	4,500
Weighted-average Remaining Contractual Life (Years)	3 years 11 months 19 days	4 years 11 months 19 days
Weighted-average Exercise Price	$ 19.085	$ 19.085
Options Exercisable Number of Options	1,082	0
Option Exercisable Weighted-average Exercise Price | (per share)	$ 19.085	$ 0	$ 19.085

X

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

X

- Definition

The exercise price of outstanding share options.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2020-01-01
-Paragraph 45
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2020-en-r&anchor=para_45_d&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_ExercisePriceOfOutstandingShareOptions2019
Namespace Prefix:	ifrs-full_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The number of share options outstanding in a share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2020-01-01
-Paragraph 45
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2020-en-r&anchor=para_45_d&doctype=Standard
-URIDate 2020-01-01

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2020-01-01
-Paragraph 45
-Subparagraph b
-Clause i
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2020-en-r&anchor=para_45_b_i&doctype=Standard
-URIDate 2020-01-01

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2020-01-01
-Paragraph 45
-Subparagraph b
-Clause vi
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2020-en-r&anchor=para_45_b_vi&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_NumberOfOutstandingShareOptions
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The number of share options exercisable in a share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2020-01-01
-Paragraph 45
-Subparagraph b
-Clause vii
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2020-en-r&anchor=para_45_b_vii&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_NumberOfShareOptionsExercisableInSharebasedPaymentArrangement
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The weighted average exercise price of share options exercisable in a share-based payment arrangement. [Refer: Weighted average [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2020-01-01
-Paragraph 45
-Subparagraph b
-Clause vii
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2020-en-r&anchor=para_45_b_vii&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_WeightedAverageExercisePriceOfShareOptionsExercisableInSharebasedPaymentArrangement2019
Namespace Prefix:	ifrs-full_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The weighted average exercise price of share options outstanding in a share-based payment arrangement. [Refer: Weighted average [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2020-01-01
-Paragraph 45
-Subparagraph b
-Clause i
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2020-en-r&anchor=para_45_b_i&doctype=Standard
-URIDate 2020-01-01

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2020-01-01
-Paragraph 45
-Subparagraph b
-Clause vi
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2020-en-r&anchor=para_45_b_vi&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_WeightedAverageExercisePriceOfShareOptionsOutstandingInSharebasedPaymentArrangement2019
Namespace Prefix:	ifrs-full_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The weighted average remaining contractual life of outstanding share options. [Refer: Weighted average [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2020-01-01
-Paragraph 45
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=2&code=ifrs-tx-2020-en-r&anchor=para_45_d&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_WeightedAverageRemainingContractualLifeOfOutstandingShareOptions2019
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=cht_CHTSecurityCoLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: