XML 255 R239.htm IDEA: XBRL DOCUMENT
v3.21.1

Segment Information - Other Segment Information (Detail) $ in Millions, $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 TWD ($) | Dec. 31, 2020 USD ($) | Dec. 31, 2019 TWD ($) | Dec. 31, 2018 TWD ($)
Disclosure of operating segments [Line Items] |  |  |  |
Share of profits of associates and joint ventures accounted for using equity method | $ 244 | $ 9 | $ 459 | $ 509
Interest income | 116 | 4 | 251 | 197
Interest expenses | 206 | 7 | 104 | 18
Operating costs and expenses | 166,843 |  | 166,747 | 171,949
Depreciation and amortization | 37,138 |  | 36,349 | 33,809
Capital expenditure | 23,511 | 838 | 24,166 | 28,550
Gain (loss) on disposal of property, plant and equipment | 1,428 | 51 | (38) | 142
Gain on disposal of investment properties | 151 | 5 | 0 | 0
Impairment loss on property, plant and equipment | 0 | 0 | 93 | 0
Reversal of impairment loss | 27 | 1 | 57 | 19
Impairment loss on intangible assets | 9 |  | 9 | 51
Impairment loss on other assets | 0 | $ 0 | 44 | 0
Domestic Fixed Communications Business [Member] |  |  |  |
Disclosure of operating segments [Line Items] |  |  |  |
Share of profits of associates and joint ventures accounted for using equity method | 0 |  | 0 | 0
Interest income | 13 |  | 15 | 18
Interest expenses | 6 |  | 5 | 0
Operating costs and expenses | 59,371 |  | 56,269 | 59,430
Depreciation and amortization | 14,250 |  | 14,842 | 15,027
Capital expenditure | 11,483 |  | 12,071 | 12,693
Gain (loss) on disposal of property, plant and equipment | 1,442 |  |  |
Gain on disposal of investment properties | 151 |  |  |
Impairment loss on property, plant and equipment |  |  | 0 |
Reversal of impairment loss | 27 |  | 57 | 19
Impairment loss on intangible assets | 0 |  | 0 | 0
Impairment loss on other assets |  |  | 13 |
Mobile Communications Business [Member] |  |  |  |
Disclosure of operating segments [Line Items] |  |  |  |
Share of profits of associates and joint ventures accounted for using equity method | 0 |  | 0 | 0
Interest income | 5 |  | 9 | 12
Interest expenses | 56 |  | 58 | 0
Operating costs and expenses | 69,211 |  | 72,952 | 73,901
Depreciation and amortization | 17,800 |  | 16,254 | 13,788
Capital expenditure | 8,827 |  | 7,773 | 10,664
Gain (loss) on disposal of property, plant and equipment | (3) |  |  |
Gain on disposal of investment properties | 0 |  |  |
Impairment loss on property, plant and equipment |  |  | 0 |
Reversal of impairment loss | 0 |  | 0 | 0
Impairment loss on intangible assets | 9 |  | 9 | 51
Impairment loss on other assets |  |  | 0 |
Internet Business [Member] |  |  |  |
Disclosure of operating segments [Line Items] |  |  |  |
Share of profits of associates and joint ventures accounted for using equity method | 0 |  | 0 | 0
Interest income | 17 |  | 20 | 19
Interest expenses | 1 |  | 1 | 0
Operating costs and expenses | 15,241 |  | 13,850 | 13,766
Depreciation and amortization | 2,669 |  | 2,914 | 3,121
Capital expenditure | 1,397 |  | 1,425 | 2,729
Gain (loss) on disposal of property, plant and equipment | 0 |  |  |
Gain on disposal of investment properties | 0 |  |  |
Impairment loss on property, plant and equipment |  |  | 0 |
Reversal of impairment loss | 0 |  | 0 | 0
Impairment loss on intangible assets | 0 |  | 0 | 0
Impairment loss on other assets |  |  | 13 |
International Fixed Communications Business [Member] |  |  |  |
Disclosure of operating segments [Line Items] |  |  |  |
Share of profits of associates and joint ventures accounted for using equity method | 0 |  | 0 | 0
Interest income | 22 |  | 41 | 28
Interest expenses | 10 |  | 12 | 0
Operating costs and expenses | 8,573 |  | 11,427 | 13,279
Depreciation and amortization | 1,450 |  | 1,547 | 1,425
Capital expenditure | 779 |  | 1,117 | 1,348
Gain (loss) on disposal of property, plant and equipment | 0 |  |  |
Gain on disposal of investment properties | 0 |  |  |
Impairment loss on property, plant and equipment |  |  | 0 |
Reversal of impairment loss | 0 |  | 0 | 0
Impairment loss on intangible assets | 0 |  | 0 | 0
Impairment loss on other assets |  |  | 0 |
Other [Member] |  |  |  |
Disclosure of operating segments [Line Items] |  |  |  |
Share of profits of associates and joint ventures accounted for using equity method | 244 |  | 459 | 509
Interest income | 59 |  | 166 | 120
Interest expenses | 133 |  | 28 | 18
Operating costs and expenses | 14,447 |  | 12,249 | 11,573
Depreciation and amortization | 969 |  | 792 | 448
Capital expenditure | 1,025 |  | 1,780 | 1,116
Gain (loss) on disposal of property, plant and equipment | (11) |  |  |
Gain on disposal of investment properties | 0 |  |  |
Impairment loss on property, plant and equipment |  |  | 93 |
Reversal of impairment loss | 0 |  | 0 | 0
Impairment loss on intangible assets | $ 0 |  | 0 | $ 0
Impairment loss on other assets |  |  | $ 18 |

X
- Definition Impairment loss on other assets. + References No definition available. + Details
Name: | cht_ImpairmentLossOnOtherAssets
Namespace Prefix: | cht_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Operating costs and expenses. + References No definition available. + Details
Name: | cht_OperatingCostsAndExpenses1
Namespace Prefix: | cht_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of depreciation and amortisation expense. Depreciation and amortisation are the systematic allocations of depreciable amounts of assets over their useful lives. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2020-01-01 -Paragraph 23 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2020-en-r&anchor=para_23_e&doctype=Standard -URIDate 2020-01-01 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2020-01-01 -Paragraph 28 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2020-en-r&anchor=para_28_e&doctype=Standard -URIDate 2020-01-01 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 12 -IssueDate 2020-01-01 -Paragraph B13 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2020-en-r&anchor=para_B13_d&doctype=Appendix&subtype=B -URIDate 2020-01-01 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 102 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_102&doctype=Standard -URIDate 2020-01-01 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 99 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_99&doctype=Standard -URIDate 2020-01-01 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 104 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_104&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_DepreciationAndAmortisationExpense
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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

X
- Definition The gains (losses) on disposals of property, plant and equipment. [Refer: Property, plant and equipment] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 98 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_98_c&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_GainsLossesOnDisposalsOfPropertyPlantAndEquipment
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The gain on disposals of investment properties. [Refer: Investment property] + 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_GainsOnDisposalsOfInvestmentProperties
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of impairment loss recognised in profit or loss for intangible assets other than goodwill. [Refer: Impairment loss recognised in profit or loss; Intangible assets other than goodwill] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 38 -IssueDate 2020-01-01 -Paragraph 118 -Subparagraph e -Clause iv -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=38&code=ifrs-tx-2020-en-r&anchor=para_118_e_iv&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_ImpairmentLossRecognisedInProfitOrLossIntangibleAssetsOtherThanGoodwill
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of impairment loss recognised in profit or loss for property, plant and equipment. [Refer: Impairment loss recognised in profit or loss; Property, plant and equipment] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 16 -IssueDate 2020-01-01 -Paragraph 73 -Subparagraph e -Clause v -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=16&code=ifrs-tx-2020-en-r&anchor=para_73_e_v&doctype=Standard -URIDate 2020-01-01 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 98 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_98_a&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_ImpairmentLossRecognisedInProfitOrLossPropertyPlantAndEquipment
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of expense arising from interest. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2020-01-01 -Paragraph 23 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2020-en-r&anchor=para_23_d&doctype=Standard -URIDate 2020-01-01 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2020-01-01 -Paragraph 28 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2020-en-r&anchor=para_28_e&doctype=Standard -URIDate 2020-01-01 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 12 -IssueDate 2020-01-01 -Paragraph B13 -Subparagraph f -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2020-en-r&anchor=para_B13_f&doctype=Appendix&subtype=B -URIDate 2020-01-01 + Details
Name: | ifrs-full_InterestExpense
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash outflow for the purchases of property, plant and equipment, classified as investing activities. [Refer: Property, plant and equipment] + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Name IAS -Number 7 -IssueDate 2020-01-01 -Paragraph 16 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=7&code=ifrs-tx-2020-en-r&anchor=para_16_a&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_PurchaseOfPropertyPlantAndEquipmentClassifiedAsInvestingActivities
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of income arising from interest. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2020-01-01 -Paragraph 23 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2020-en-r&anchor=para_23_c&doctype=Standard -URIDate 2020-01-01 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2020-01-01 -Paragraph 28 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2020-en-r&anchor=para_28_e&doctype=Standard -URIDate 2020-01-01 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 12 -IssueDate 2020-01-01 -Paragraph B13 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2020-en-r&anchor=para_B13_e&doctype=Appendix&subtype=B -URIDate 2020-01-01 Reference 4: 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_RevenueFromInterest
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of reversal of impairment loss recognised in profit or loss for investment property. [Refer: Reversal of impairment loss recognised in profit or loss; Investment property] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 40 -IssueDate 2020-01-01 -Paragraph 76 -Subparagraph g -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=40&code=ifrs-tx-2020-en-r&anchor=para_76_g&doctype=Standard -URIDate 2020-01-01 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 40 -IssueDate 2020-01-01 -Paragraph 79 -Subparagraph d -Clause v -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=40&code=ifrs-tx-2020-en-r&anchor=para_79_d_v&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_ReversalOfImpairmentLossRecognisedInProfitOrLossInvestmentProperty
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entity's share of the profit (loss) of associates and joint ventures accounted for using the equity method. [Refer: Associates [member]; Investments accounted for using equity method; Joint ventures [member]; Profit (loss)] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2020-01-01 -Paragraph 23 -Subparagraph g -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2020-en-r&anchor=para_23_g&doctype=Standard -URIDate 2020-01-01 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 8 -IssueDate 2020-01-01 -Paragraph 28 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=8&code=ifrs-tx-2020-en-r&anchor=para_28_e&doctype=Standard -URIDate 2020-01-01 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Note Effective on first application of IFRS 9 -Name IFRS -Number 4 -IssueDate 2020-01-01 -Paragraph 39M -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=4&code=ifrs-tx-2020-en-b&anchor=para_39M_b&doctype=Standard -URIDate 2020-01-01 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 82 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_82_c&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_ShareOfProfitLossOfAssociatesAndJointVenturesAccountedForUsingEquityMethod
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | ifrs-full_SegmentsAxis=cht_DomesticFixedCommunicationsBusinessMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SegmentsAxis=cht_MobileCommunicationsBusinessMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SegmentsAxis=cht_InternetBusinessMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SegmentsAxis=cht_InternationalFixedCommunicationsBusinessMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SegmentsAxis=ifrs-full_AllOtherSegmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |