XML 166 R152.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Equity - Adjustments of Additional Paid-in Capital (Detail) $ in Millions, $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 TWD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2016 TWD ($) | Dec. 31, 2015 TWD ($)
Beginning balance | $ 366,928 |  | $ 369,339 | $ 365,712
Partial disposal of interests in subsidiaries | 106 |  | 83 | 45
Unclaimed dividend | 3 |  |  |
Change in additional paid-in capital from investments in associates and joint ventures accounted for using equity method | 0 |  |  |
Change in additional paid-in capital for not participating in the capital increase of a subsidiary | 2,552 |  | 1,175 |
Other changes in additional paid-in capital in subsidiaries | 0 |  |  | 3
Subsidiary purchased its treasury stock |  |  |  | (492)
Share-based payment transactions of subsidiaries | 22 |  | 17 | 36
Ending balance | 369,410 | $ 12,463 | 366,928 | 369,339
Share premium [Member] |  |  |  |
Beginning balance | 126,045 |  | 126,045 | 126,045
Ending balance | 126,045 |  | 126,045 | 126,045
Movements of additional paid-in capital arising from changes in equities of subsidiaries [Member] |  |  |  |
Beginning balance | 389 |  | 0 | 14
Partial disposal of interests in subsidiaries | 1 |  | 0 | 0
Change in additional paid-in capital for not participating in the capital increase of a subsidiary | 802 |  | 389 |
Other changes in additional paid-in capital in subsidiaries | 0 |  |  | 1
Subsidiary purchased its treasury stock |  |  |  | (15)
Share-based payment transactions of subsidiaries | 2 |  | 0 |
Treasury stock transfer of subsidiaries | 27 |  |  |
Ending balance | 1,221 |  | 389 | 0
Difference between consideration received and carrying amount of the subsidiaries' net assets upon disposal [Member] |  |  |  |
Beginning balance | 85 |  | 27 | 0
Partial disposal of interests in subsidiaries | 76 |  | 58 | 27
Ending balance | 161 |  | 85 | 27
Donated capital [Member] |  |  |  |
Beginning balance | 13 |  | 13 | 13
Unclaimed dividend | 3 |  |  |
Ending balance | 16 |  | 13 | 13
Stockholders' contribution due to privatization [Member] |  |  |  |
Beginning balance | 20,648 |  | 20,648 | 20,648
Ending balance | 20,648 |  | 20,648 | 20,648
Additional paid-in capital [Member] |  |  |  |
Beginning balance | 147,180 |  | 146,733 | 146,720
Partial disposal of interests in subsidiaries | 77 |  | 58 | 27
Unclaimed dividend | 3 |  |  |
Change in additional paid-in capital from investments in associates and joint ventures accounted for using equity method | 0 |  |  |
Change in additional paid-in capital for not participating in the capital increase of a subsidiary | 802 |  | 389 |
Other changes in additional paid-in capital in subsidiaries | 0 |  |  | 1
Subsidiary purchased its treasury stock |  |  |  | (15)
Share-based payment transactions of subsidiaries | 2 |  | 0 | 0
Treasury stock transfer of subsidiaries | 27 |  |  |
Ending balance | $ 148,091 | $ 4,996 | $ 147,180 | $ 146,733

X
- Definition Increase (decrease) in additional paid-in capital for not participating in capital increase of subsidiary. + References No definition available. + Details
Name: | cht_IncreaseDecreaseInAdditionalPaidinCapitalForNotParticipatingInCapitalIncreaseOfSubsidiary
Namespace Prefix: | cht_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Increase (decrease) in additional paid-in capital from investments in associates and joint ventures accounted for using equity method. + References No definition available. + Details
Name: | cht_IncreaseDecreaseInAdditionalPaidinCapitalFromInvestmentsInAssociatesAndJointVenturesAccountedForUsingEquityMethod
Namespace Prefix: | cht_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Increase (decrease) through unclaimed dividend. + References No definition available. + Details
Name: | cht_IncreaseDecreaseThroughUnclaimedDividend
Namespace Prefix: | cht_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Purchase of treasury shares by subsidiary. + References No definition available. + Details
Name: | cht_PurchaseOfTreasurySharesBySubsidiary
Namespace Prefix: | cht_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Transfer of treasury stock of subsidiaries. + References No definition available. + Details
Name: | cht_TransferOfTreasuryStockOfSubsidiaries
Namespace Prefix: | cht_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of residual interest in the assets of the entity after deducting all its liabilities. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 1 -IssueDate 2016-01-13 -Paragraph 24 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=1&date=2016-03-30&anchor=para_24_a&doctype=Standard -URIDate 2016-03-31 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 1 -IssueDate 2016-01-13 -Paragraph 32 -Subparagraph a -Clause i -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=1&date=2016-03-30&anchor=para_32_a_i&doctype=Standard -URIDate 2016-03-31 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2016-01-13 -Paragraph 93 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=13&date=2016-03-30&anchor=para_93_a&doctype=Standard -URIDate 2016-03-31 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2016-01-13 -Paragraph 93 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=13&date=2016-03-30&anchor=para_93_b&doctype=Standard -URIDate 2016-03-31 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 13 -IssueDate 2016-01-13 -Paragraph 93 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=13&date=2016-03-30&anchor=para_93_e&doctype=Standard -URIDate 2016-03-31 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2016-01-13 -Paragraph 55 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2016-03-30&anchor=para_55&doctype=Standard -URIDate 2016-03-31 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2016-01-13 -Paragraph 78 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2016-03-30&anchor=para_78_e&doctype=Standard -URIDate 2016-03-31 + Details
Name: | ifrs-full_Equity
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The increase (decrease) in equity resulting from the disposal of subsidiaries. [Refer: Subsidiaries [member]] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2016-01-13 -Paragraph 106 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2016-03-30&anchor=para_106_d&doctype=Standard -URIDate 2016-03-31 + Details
Name: | ifrs-full_IncreaseDecreaseThroughDisposalOfSubsidiary
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The increase (decrease) in equity resulting from share-based payment transactions. [Refer: Equity] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2016-01-13 -Paragraph 106 -Subparagraph d -Clause iii -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2016-03-30&anchor=para_106_d_iii&doctype=Standard -URIDate 2016-03-31 + Details
Name: | ifrs-full_IncreaseDecreaseThroughSharebasedPaymentTransactions
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The increase (decrease) in equity resulting from changes that the entity does not separately disclose in the same statement or note. [Refer: Equity] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2016-01-13 -Paragraph 106 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2016-03-30&anchor=para_106_d&doctype=Standard -URIDate 2016-03-31 + Details
Name: | ifrs-full_IncreaseDecreaseThroughTransfersAndOtherChangesEquity
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | ifrs-full_ComponentsOfEquityAxis=ifrs-full_SharePremiumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ComponentsOfEquityAxis=cht_MovementsOfAdditionalPaidinCapitalArisingFromChangesInEquitiesOfSubsidiariesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ComponentsOfEquityAxis=cht_DifferenceBetweenConsiderationReceivedAndCarryingAmountOfSubsidiariesNetAssetsUponDisposalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ComponentsOfEquityAxis=cht_DonatedCapitalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ComponentsOfEquityAxis=cht_StockholdersContributionDueToPrivatizationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ComponentsOfEquityAxis=ifrs-full_AdditionalPaidinCapitalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |