XML 142 R126.htm IDEA: XBRL DOCUMENT
v3.21.1

Property, Plant and Equipment - Summary of Assets Used by the Company (Detail) $ in Millions, $ in Millions | Dec. 31, 2020 TWD ($) | Dec. 31, 2020 USD ($) | Dec. 31, 2019 TWD ($) | Dec. 31, 2018 TWD ($)
--- | --- | --- | --- | ---
Disclosure Of Property Plant And Equipment [Line Items] |  |  |  |
Assets used by the Company | $ 281,416 | $ 10,022 | $ 283,694 | $ 288,914
Assets Subject to Operating Leases [Member] |  |  |  |
Disclosure Of Property Plant And Equipment [Line Items] |  |  |  |
Assets used by the Company | 7,593 |  | 7,324 |
Assets Used by the Company [Member] |  |  |  |
Disclosure Of Property Plant And Equipment [Line Items] |  |  |  |
Assets used by the Company | $ 273,823 |  | $ 276,370 |

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

X
- Definition The amount of tangible assets that: (a) are held for use in the production or supply of goods or services, for rental to others, or for administrative purposes; and (b) are expected to be used during more than one period. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 73 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_73_e&doctype=Standard -URIDate 2020-01-01 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 54 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_54_a&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_PropertyPlantAndEquipment
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | ifrs-full_PropertyPlantAndEquipmentByOperatingLeaseStatusAxis=ifrs-full_PropertyPlantAndEquipmentSubjectToOperatingLeasesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CategoriesOfRelatedPartiesAxis=cht_PropertyPlantAndEquipmentUsedByCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |