XML 225 R210.htm IDEA: XBRL DOCUMENT
v3.19.1

Fair Value Information - Schedule of Reconciliations for Financial Assets (Detail) - TWD ($) $ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2018 | Jan. 01, 2018 | Dec. 31, 2017
Disclosure Of Fair Value Measurement Of Assets [Line Items] |  |  |
Effect of retrospective application of IFRS 9 |  |  | $ 883
Level 3 [Member] |  |  |
Disclosure Of Fair Value Measurement Of Assets [Line Items] |  |  |
Foreign currency denominated monetary assets | $ 4,550 | $ 4,468 |
Effect of retrospective application of IFRS 9 |  | 4,468 |
Acquisition | 290 |  |
Recognized in profit or loss under “Other gains and losses” | (26) |  |
Recognized in other comprehensive income under “Unrealized gain or loss on investments in equity instruments at fair value through other comprehensive income” | (175) |  |
Proceeds from return of investees | (7) |  |
Level 3 [Member] | Measured at Fair Value Through Profit or Loss [Member] |  |  |
Disclosure Of Fair Value Measurement Of Assets [Line Items] |  |  |
Foreign currency denominated monetary assets | 517 | 543 |
Effect of retrospective application of IFRS 9 |  | 543 |
Recognized in profit or loss under “Other gains and losses” | (26) |  |
Unrealized loss in 2018 | (26) |  |
Level 3 [Member] | FVOCI [Member] |  |  |
Disclosure Of Fair Value Measurement Of Assets [Line Items] |  |  |
Foreign currency denominated monetary assets | 4,033 | 3,925 |
Effect of retrospective application of IFRS 9 |  | $ 3,925 |
Acquisition | 290 |  |
Recognized in other comprehensive income under “Unrealized gain or loss on investments in equity instruments at fair value through other comprehensive income” | (175) |  |
Proceeds from return of investees | $ (7) |  |

X
- Definition Acquisition. + References No definition available. + Details
Name: | cht_Acquisition
Namespace Prefix: | cht_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Proceeds from return of investees. + References No definition available. + Details
Name: | cht_ProceedsFromReturnOfInvestees
Namespace Prefix: | cht_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Recognized in other comprehensive income under unrealized gain or loss on investments in equity instruments at fair value through other comprehensive income. + References No definition available. + Details
Name: | cht_RecognizedInOtherComprehensiveIncomeUnderUnrealizedGainOrLossOnInvestmentsInEquityInstrumentsAtFairValueThroughOtherComprehensiveIncome
Namespace Prefix: | cht_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Recognized in profit or loss under “other gains and losses”. + References No definition available. + Details
Name: | cht_RecognizedInProfitOrLossUnderOtherGainsAndLosses
Namespace Prefix: | cht_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Unrealized loss in current year. + References No definition available. + Details
Name: | cht_UnrealizedLossInCurrentYear
Namespace Prefix: | cht_
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_DisclosureOfFairValueMeasurementOfAssetsLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of assets that are: (a) cash; (b) an equity instrument of another entity; (c) a contractual right: (i) to receive cash or another financial asset from another entity; or (ii) to exchange financial assets or financial liabilities with another entity under conditions that are potentially favourable to the entity; or (d) a contract that will, or may be, settled in the entity’s own equity instruments and is: (i) a non-derivative for which the entity is, or may be, obliged to receive a variable number of the entity’s own equity instruments; or (ii) a derivative that will, or may be, settled other than by the exchange of a fixed amount of cash or another financial asset for a fixed number of the entity’s own equity instruments. For this purpose the entity’s own equity instruments do not include puttable financial instruments classified as equity instruments in accordance with paragraphs 16A-16B of IAS 32, instruments that impose on the entity an obligation to deliver to another party a pro rata share of the net assets of the entity only on liquidation and are classified as equity instruments in accordance with paragraphs 16C-16D of IAS 32, or instruments that are contracts for the future receipt or delivery of the entity’s own equity instruments. [Refer: Financial instruments, class [member]; Financial liabilities] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2018-01-01 -Paragraph 25 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2018-03-01&anchor=para_25&doctype=Standard -URIDate 2018-03-16 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2018-01-01 -Paragraph 35H -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2018-03-01&anchor=para_35H&doctype=Standard -URIDate 2018-03-16 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2018-01-01 -Paragraph 35I -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2018-03-01&anchor=para_35I&doctype=Standard -URIDate 2018-03-16 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2018-01-01 -Paragraph 35M -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2018-03-01&anchor=para_35M&doctype=Standard -URIDate 2018-03-16 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Name IFRS -Number 7 -IssueDate 2018-01-01 -Paragraph 35N -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2018-03-01&anchor=para_35N&doctype=Standard -URIDate 2018-03-16 + Details
Name: | ifrs-full_FinancialAssets
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The increase (decrease) in financial assets arising from a change in measurement attribute on the entity's transition to IFRS 9. [Refer: Financial assets] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2018-01-01 -Paragraph 42L -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2018-03-01&anchor=para_42L_b&doctype=Standard -URIDate 2018-03-16 + Details
Name: | ifrs-full_IncreaseDecreaseInFinancialAssetsArisingFromChangeInMeasurementAttributeFirstApplicationOfIFRS9
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | ifrs-full_LevelsOfFairValueHierarchyAxis=ifrs-full_Level3OfFairValueHierarchyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CategoriesOfFinancialAssetsAxis=ifrs-full_FinancialAssetsAtFairValueThroughProfitOrLossCategoryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CategoriesOfFinancialAssetsAxis=ifrs-full_FinancialAssetsAtFairValueThroughOtherComprehensiveIncomeCategoryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |