XML 157 R127.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Risk Management Activities - Non-Hedges (Details) € in Millions, $ in Millions, $ in Millions, $ in Millions | Dec. 31, 2021 CAD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2021 AUD ($) | Dec. 31, 2021 EUR (€) | Dec. 31, 2020 CAD ($) | Dec. 31, 2020 USD ($) | Dec. 31, 2020 AUD ($) | Dec. 31, 2020 EUR (€)
--- | --- | --- | --- | --- | --- | --- | --- | ---
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Hedging instrument, assets | $ 2 |  |  |  | $ 2 |  |  |
Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2022-2025, Contract One |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Hedging instrument, liabilities | (5) |  |  |  |  |  |  |
Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2022-2025, Contract Two |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Hedging instrument, assets | 8 |  |  |  |  |  |  |
Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2022, Contract One |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Hedging instrument, assets |  |  |  |  |  |  |  |
Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2022, Contract Two |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Hedging instrument, assets |  |  |  |  |  |  |  |
Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2021-2024, Contract One |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Hedging instrument, liabilities |  |  |  |  | (14) |  |  |
Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2021-2024, Contract Two |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Hedging instrument, assets |  |  |  |  | 9 |  |  |
Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2021, Contract One |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Hedging instrument, assets |  |  |  |  | 0 |  |  |
Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2021, Contract Two |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Hedging instrument, assets |  |  |  |  | 0 |  |  |
Foreign exchange forward contracts – foreign-denominated debt | Discontinued Hedge Positions | Currency risk | Maturity, 2022 |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Hedging instrument, assets | 1 |  |  |  | 2 |  |  |
Australia, Dollars | Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2022-2025, Contract One |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Notional amount sold |  |  | $ 28 |  |  |  |  |
Australia, Dollars | Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2022, Contract One |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Notional amount sold |  |  |  |  |  |  |  |
Australia, Dollars | Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2021-2024, Contract One |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Notional amount sold |  |  |  |  |  |  | $ 197 |
Australia, Dollars | Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2021, Contract One |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Notional amount sold |  |  |  |  |  |  | $ 4 |
Canada, Dollars | Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2022-2025, Contract One |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Derivative, notional amount purchased | 26 |  |  |  |  |  |  |
Canada, Dollars | Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2022-2025, Contract Two |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Derivative, notional amount purchased | 357 |  |  |  |  |  |  |
Canada, Dollars | Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2022, Contract Two |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Notional amount sold |  |  |  |  |  |  |  |
Canada, Dollars | Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2021-2024, Contract One |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Derivative, notional amount purchased |  |  |  |  | 181 |  |  |
Canada, Dollars | Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2021-2024, Contract Two |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Derivative, notional amount purchased |  |  |  |  | 72 |  |  |
Canada, Dollars | Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2021, Contract Two |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Notional amount sold |  |  |  |  | 1 |  |  |
Canada, Dollars | Foreign exchange forward contracts – foreign-denominated debt | Discontinued Hedge Positions | Currency risk | Maturity, 2022 |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Notional amount sold | $ 191 |  |  |  | $ 191 |  |  |
U.S. Dollars | Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2022-2025, Contract Two |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Notional amount sold |  | $ 271 |  |  |  |  |  |
U.S. Dollars | Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2022, Contract One |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Derivative, notional amount purchased |  |  |  |  |  |  |  |
U.S. Dollars | Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2021-2024, Contract Two |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Notional amount sold |  |  |  |  |  | $ 47 |  |
U.S. Dollars | Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2021, Contract One |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Derivative, notional amount purchased |  |  |  |  |  | 3 |  |
U.S. Dollars | Foreign exchange forward contracts – foreign-denominated debt | Discontinued Hedge Positions | Currency risk | Maturity, 2022 |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Derivative, notional amount purchased |  | $ 150 |  |  |  | $ 150 |  |
Euro Member Countries, Euro | Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2022, Contract Two |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Derivative, notional amount purchased | € |  |  |  |  |  |  |  |
Euro Member Countries, Euro | Foreign exchange forward contracts – foreign-denominated receipts/expenditures | Discontinued Hedge Positions | Currency risk | Maturity, 2021, Contract Two |  |  |  |  |  |  |  |
Disclosure of detailed information about hedges [line items] |  |  |  |  |  |  |  |
Derivative, notional amount purchased | € |  |  |  |  |  |  |  | € 1

X
- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table. + References No definition available. + Details
Name: | ifrs-full_DisclosureOfHedgeAccountingLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of a hedging instrument, recognised as an asset. [Refer: Hedging instruments [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2021-01-01 -Paragraph 24A -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_24A_a&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_HedgingInstrumentAssets
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The amount of a hedging instrument, recognised as a liability. [Refer: Hedging instruments [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2021-01-01 -Paragraph 24A -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_24A_a&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_HedgingInstrumentLiabilities
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Derivative, Notional Amount Purchased + References No definition available. + Details
Name: | tac_DerivativeNotionalAmountPurchased
Namespace Prefix: | tac_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Derivative, Notional Amount Sold + References No definition available. + Details
Name: | tac_DerivativeNotionalAmountSold
Namespace Prefix: | tac_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | ifrs-full_HedgingInstrumentsAxis=tac_ForeignExchangeForwardContractsForeignDenominatedReceiptsExpendituresMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfHedgesAxis=tac_DiscontinuedHedgePositionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfRisksAxis=ifrs-full_CurrencyRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MaturityAxis=tac_Maturity20222025ContractOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MaturityAxis=tac_Maturity20222025ContractTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MaturityAxis=tac_Maturity2022ContractOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MaturityAxis=tac_Maturity2022ContractTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MaturityAxis=tac_Maturity20212024ContractOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MaturityAxis=tac_Maturity20212024ContractTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MaturityAxis=tac_Maturity2021ContractOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MaturityAxis=tac_Maturity2021ContractTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_HedgingInstrumentsAxis=tac_ForeignExchangeForwardContractsForeignDenominatedDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_MaturityAxis=tac_Maturity2022Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CurrencyAxis=currency_AUD
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CurrencyAxis=currency_CAD
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CurrencyAxis=currency_USD
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CurrencyAxis=currency_EUR
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |