XML 206 R191.htm IDEA: XBRL DOCUMENT
v3.19.1

Share-based Payments Arrangement - SENAO's Employee Stock Options Outstanding (Detail) - Senao International Co., Ltd. (SENAO) [Member] | Dec. 31, 2018 TWD ($) yr | Jul. 31, 2018 TWD ($) | Jun. 30, 2018 TWD ($) | Dec. 31, 2017 TWD ($) yr | Jul. 31, 2017 TWD ($) | Jun. 30, 2017 TWD ($) | Dec. 31, 2016 TWD ($) | Jul. 31, 2016 TWD ($) | Jun. 30, 2016 TWD ($) | Dec. 31, 2015 TWD ($)
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Disclosure of range of exercise prices of outstanding share options [Line Items] |  |  |  |  |  |  |  |  |  |
Range of Exercise Price | $ 66.20 | $ 66.20 | $ 70.70 | $ 70.70 | $ 70.70 | $ 76.10 |  | $ 76.10 | $ 81.40 |
Number of Options Outstanding | 5,318,000 |  |  | 5,926,000 |  |  | 6,587,000 |  |  | 7,787,000
Weighted-average Remaining Contractual Life (Years) | yr | 0.35 |  |  | 1.35 |  |  |  |  |  |
Weighted-average Exercise Price | $ 66.20 |  |  | $ 70.70 |  |  | $ 76.10 |  |  | $ 81.40
Options Exercisable Number of Options | 5,318,000 |  |  | 5,926,000 |  |  | 4,947,000 |  |  |
Option Exercisable Weighted-average Exercise Price | $ 66.20 |  |  | $ 70.70 |  |  | $ 76.10 |  |  |

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 2018-01-01 -Paragraph 45 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_d&doctype=Standard -URIDate 2018-03-16 + Details
Name: | ifrs-full_ExercisePriceOfOutstandingShareOptions
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
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 2018-01-01 -Paragraph 45 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_d&doctype=Standard -URIDate 2018-03-16 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 2 -IssueDate 2018-01-01 -Paragraph 45 -Subparagraph b -Clause i -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_b_i&doctype=Standard -URIDate 2018-03-16 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 2 -IssueDate 2018-01-01 -Paragraph 45 -Subparagraph b -Clause vi -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_b_vi&doctype=Standard -URIDate 2018-03-16 + 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 2018-01-01 -Paragraph 45 -Subparagraph b -Clause vii -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_b_vii&doctype=Standard -URIDate 2018-03-16 + 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 2018-01-01 -Paragraph 45 -Subparagraph b -Clause vii -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_b_vii&doctype=Standard -URIDate 2018-03-16 + Details
Name: | ifrs-full_WeightedAverageExercisePriceOfShareOptionsExercisableInSharebasedPaymentArrangement
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
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 2018-01-01 -Paragraph 45 -Subparagraph b -Clause i -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_b_i&doctype=Standard -URIDate 2018-03-16 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 2 -IssueDate 2018-01-01 -Paragraph 45 -Subparagraph b -Clause vi -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_b_vi&doctype=Standard -URIDate 2018-03-16 + Details
Name: | ifrs-full_WeightedAverageExercisePriceOfShareOptionsOutstandingInSharebasedPaymentArrangement
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
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 2018-01-01 -Paragraph 45 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2018-03-01&anchor=para_45_d&doctype=Standard -URIDate 2018-03-16 + Details
Name: | ifrs-full_WeightedAverageRemainingContractualLifeOfOutstandingShareOptions
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | ifrs-full_SignificantInvestmentsInSubsidiariesAxis=cht_SenaoInternationalCoLtdMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |