XML 163 R133.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Risk Management Activities - Hedged items on the statement of financial position (Details) MWh in Millions, $ in Millions, $ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2021 CAD ($) | Dec. 31, 2020 CAD ($) | Dec. 31, 2021 USD ($) MWh | Dec. 31, 2021 CAD ($) MWh | Dec. 31, 2020 USD ($) MWh | Dec. 31, 2020 CAD ($) MWh
Disclosure of detailed information about hedging instruments [line items] |  |  |  |  |  |
Hedging instrument, assets |  |  |  | $ 2 |  | $ 2
Physical power sales | Cash flow hedges | Commodity risk management |  |  |  |  |  |
Disclosure of detailed information about hedging instruments [line items] |  |  |  |  |  |
Notional amount purchased | MWh |  |  | 13 | 13 | 16 | 16
Hedging instrument, assets |  |  |  | $ 285 |  | $ 573
Gain (loss) on hedge ineffectiveness | $ (181) | $ (33) |  |  |  |
Reserve of cash flow hedges |  |  |  | 226 |  | 417
Interest Expense On Long-Term Debt | Cash flow hedges | Interest rate risk |  |  |  |  |  |
Disclosure of detailed information about hedging instruments [line items] |  |  |  |  |  |
Gain (loss) on hedge ineffectiveness | 3 | 7 |  |  |  |
Reserve of cash flow hedges |  |  |  | 2 |  | 19
Foreign-denominated debt | Net Investment Hedge | Currency risk |  |  |  |  |  |
Disclosure of detailed information about hedging instruments [line items] |  |  |  |  |  |
Hedging instrument, assets |  |  |  | 473 |  | 472
Gain (loss) on hedge ineffectiveness | 0 | 11 |  |  |  |
Foreign-denominated debt | Net Investment Hedge | Currency risk | U.S. Dollars |  |  |  |  |  |
Disclosure of detailed information about hedging instruments [line items] |  |  |  |  |  |
Notional amount |  |  | $ 370 |  | $ 370 |
Interest rate swap | Cash flow hedges | Interest rate risk | U.S. Dollars |  |  |  |  |  |
Disclosure of detailed information about hedging instruments [line items] |  |  |  |  |  |
Notional amount |  |  | 300 |  | $ 150 |
Hedging instrument, liabilities |  |  |  | 3 |  | (3)
Gain (loss) on hedge ineffectiveness | 3 | 3 |  |  |  |
Interest rate swap | Cash flow hedges | Interest rate risk | Canada, Dollars |  |  |  |  |  |
Disclosure of detailed information about hedging instruments [line items] |  |  |  |  |  |
Notional amount |  |  |  |  |  | 75
Hedging instrument, liabilities |  |  |  |  |  | $ (4)
Gain (loss) on hedge ineffectiveness |  | $ 4 |  |  |  |
Foreign-Denominated Expenditures | Cash flow hedges | Interest rate risk | U.S. Dollars | Minimum |  |  |  |  |  |
Disclosure of detailed information about hedging instruments [line items] |  |  |  |  |  |
Notional amount |  |  | 8 |  |  |
Hedging instrument, liabilities |  |  |  | 0 |  |
Gain (loss) on hedge ineffectiveness | 0 |  |  |  |  |
Foreign-Denominated Expenditures | Cash flow hedges | Interest rate risk | U.S. Dollars | Maximum |  |  |  |  |  |
Disclosure of detailed information about hedging instruments [line items] |  |  |  |  |  |
Notional amount |  |  | $ 14 |  |  |
Hedging instrument, liabilities |  |  |  | $ 0 |  |
Gain (loss) on hedge ineffectiveness | $ 0 |  |  |  |  |

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

X
- Definition The gain (loss) on hedge ineffectiveness. Hedge ineffectiveness is the extent to which the changes in the fair value or the cash flows of the hedging instrument are greater or less than those on the hedged item. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 7 -IssueDate 2021-01-01 -Paragraph 24C -Subparagraph a -Clause i -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_24C_a_i&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_GainLossOnHedgeIneffectiveness
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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 The nominal or face amount of a financial instrument, used to calculate payments made on that instrument. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_112_c&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_NotionalAmount
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition A component of equity representing the accumulated portion of gain (loss) on a hedging instrument that is determined to be an effective hedge for cash flow hedges. [Refer: Cash flow hedges [member]] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2021-01-01 -Paragraph 78 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2021-en-r&anchor=para_78_e&doctype=Standard -URIDate 2021-03-24 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 9 -IssueDate 2021-01-01 -Paragraph 6.5.11 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=9&code=ifrs-tx-2021-en-r&anchor=para_6.5.11&doctype=Standard -URIDate 2021-03-24 + Details
Name: | ifrs-full_ReserveOfCashFlowHedges
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Derivative, Nonmonetary Notional Amount Purchased Per Hour + References No definition available. + Details
Name: | tac_DerivativeNonmonetaryNotionalAmountPurchasedPerHour
Namespace Prefix: | tac_
Data Type: | num:energyItemType
Balance Type: | na
Period Type: | instant

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

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

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

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

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

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

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

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

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_BottomOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_TopOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |