XML 186 R153.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Exchangeable Securities (Details) - CAD ($) $ in Millions |  |  |  | 1 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | ---
May 25, 2019 | May 01, 2019 | Mar. 25, 2019 | Oct. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Disclosure of detailed information about borrowings [line items] |  |  |  |  |  |  |
Proceeds on sale of Wintering Hills facility and Solomon disposition (Note 4) |  |  |  |  | $ 0 | $ 2 | $ 478
Notes and debentures issued |  |  |  |  | 350 |  |
Gross carrying amount |  |  |  |  |  |  |
Disclosure of detailed information about borrowings [line items] |  |  |  |  |  |  |
Notes and debentures issued |  |  |  |  | $ 326 |  |
7% Unsecured Subordinated Debentures Due May 1, 2039 |  |  |  |  |  |  |
Disclosure of detailed information about borrowings [line items] |  |  |  |  |  |  |
Interest rate |  | 7.00% |  |  | 7.00% |  |
Brookfield Renewable Partners | Investment Agreement |  |  |  |  |  |  |
Disclosure of detailed information about borrowings [line items] |  |  |  |  |  |  |
Proceeds on sale of Wintering Hills facility and Solomon disposition (Note 4) | $ 750 |  | $ 750 |  |  |  |
Other cash receipts from sales of equity or debt instruments of other entities, classified as investing activities |  | $ 350 |  | $ 400 |  |  |

X
- Definition The interest rate on borrowings. [Refer: Borrowings] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IFRS -Number 7 -IssueDate 2018-01-01 -Paragraph 7 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2018-03-01&anchor=para_7&doctype=Standard -URIDate 2018-03-16 + Details
Name: | ifrs-full_BorrowingsInterestRate
Namespace Prefix: | ifrs-full_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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

X
- Definition The amount of notes and debentures issued by the entity. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2018-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_112_c&doctype=Standard -URIDate 2018-03-16 + Details
Name: | ifrs-full_NotesAndDebenturesIssued
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The cash inflow from sales of equity or debt instruments of other entities (other than receipts for those instruments considered to be cash equivalents and those held for dealing or trading purposes), classified as investing activities. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Name IAS -Number 7 -IssueDate 2018-01-01 -Paragraph 16 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=7&date=2018-03-01&anchor=para_16_d&doctype=Standard -URIDate 2018-03-16 + Details
Name: | ifrs-full_OtherCashReceiptsFromSalesOfEquityOrDebtInstrumentsOfOtherEntitiesClassifiedAsInvestingActivities
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash inflow from sales of investments accounted for using the equity method. [Refer: Investments accounted for using equity method] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 7 -IssueDate 2018-01-01 -Paragraph 16 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=7&date=2018-03-01&anchor=para_16&doctype=Standard -URIDate 2018-03-16 + Details
Name: | ifrs-full_ProceedsFromSalesOfInvestmentsAccountedForUsingEquityMethod
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | ifrs-full_CarryingAmountAccumulatedDepreciationAmortisationAndImpairmentAndGrossCarryingAmountAxis=ifrs-full_GrossCarryingAmountMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_BorrowingsByNameAxis=tac_SevenPercentUnsecuredSubordinatedDebenturesDueMay12039Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=tac_BrookfieldRenewablePartnersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentAxis=tac_InvestmentAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |