XML 202 R169.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Employee Future Benefits - Costs Recognized (Details) - CAD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Disclosure of net defined benefit liability (asset) [line items] |  |  |
Current service cost | $ 2 | $ 2 | $ 6
Administration expenses | 1 | 1 | 1
Defined benefit expense | 10 | 10 | 6
Defined contribution expense | 11 | 11 | 8
Net expense | 21 | 21 | 14
Interest cost on defined benefit obligation |  |  |
Disclosure of net defined benefit liability (asset) [line items] |  |  |
Interest cost on defined benefit obligation | 21 | 16 | 14
Plan assets |  |  |
Disclosure of net defined benefit liability (asset) [line items] |  |  |
Interest on plan assets | (14) | (9) | (8)
Curtailment and amendment gain |  |  | (7)
Registered |  |  |
Disclosure of net defined benefit liability (asset) [line items] |  |  |
Current service cost | 1 | 1 | 3
Administration expenses | 1 | 1 | 1
Defined benefit expense | 5 | 6 | 1
Defined contribution expense | 11 | 11 | 8
Net expense | 16 | 17 | 9
Registered | Interest cost on defined benefit obligation |  |  |
Disclosure of net defined benefit liability (asset) [line items] |  |  |
Interest cost on defined benefit obligation | 16 | 13 | 12
Registered | Plan assets |  |  |
Disclosure of net defined benefit liability (asset) [line items] |  |  |
Interest on plan assets | (13) | (9) | (8)
Curtailment and amendment gain |  |  | (7)
Supplemental |  |  |
Disclosure of net defined benefit liability (asset) [line items] |  |  |
Current service cost | 1 | 1 | 2
Administration expenses | 0 | 0 | 0
Defined benefit expense | 4 | 4 | 4
Defined contribution expense | 0 | 0 | 0
Net expense | 4 | 4 | 4
Supplemental | Interest cost on defined benefit obligation |  |  |
Disclosure of net defined benefit liability (asset) [line items] |  |  |
Interest cost on defined benefit obligation | 4 | 3 | 2
Supplemental | Plan assets |  |  |
Disclosure of net defined benefit liability (asset) [line items] |  |  |
Interest on plan assets | (1) | 0 | 0
Curtailment and amendment gain |  |  | 0
Other |  |  |
Disclosure of net defined benefit liability (asset) [line items] |  |  |
Current service cost | 0 | 0 | 1
Administration expenses | 0 | 0 | 0
Defined benefit expense | 1 | 0 | 1
Defined contribution expense | 0 | 0 | 0
Net expense | 1 | 0 | 1
Other | Interest cost on defined benefit obligation |  |  |
Disclosure of net defined benefit liability (asset) [line items] |  |  |
Interest cost on defined benefit obligation | 1 | 0 | 0
Other | Plan assets |  |  |
Disclosure of net defined benefit liability (asset) [line items] |  |  |
Interest on plan assets | $ 0 | $ 0 | 0
Curtailment and amendment gain |  |  | $ 0

X
- Definition The expense of employee service in the current period arising from defined benefit plans. [Refer: Post-employment benefit expense in profit or loss, defined benefit plans] [Contrast: Increase in net defined benefit liability (asset) resulting from current service cost] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 19 -IssueDate 2023-01-01 -Paragraph 135 -Subparagraph b -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2023-en-r&anchor=para_135_b&doctype=Standard -URIDate 2023-03-23 + Details
Name: | ifrs-full_CurrentServiceCostDefinedBenefitPlans
Namespace Prefix: | ifrs-full_
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 members defined in one or many axes of the table. + References No definition available. + Details
Name: | ifrs-full_DisclosureOfNetDefinedBenefitLiabilityAssetLineItems
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The expense of all forms of consideration given by an entity in exchange for a service rendered by employees or for the termination of employment. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Name IAS -Number 1 -IssueDate 2023-01-01 -Paragraph 102 -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_102&doctype=Standard -URIDate 2023-03-23 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2023-01-01 -Paragraph 99 -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_99&doctype=Standard -URIDate 2023-03-23 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2023-01-01 -Paragraph 104 -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_104&doctype=Standard -URIDate 2023-03-23 + Details
Name: | ifrs-full_EmployeeBenefitsExpense
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of interest expense arising from defined benefit plans. [Refer: Interest expense; Post-employment benefit expense in profit or loss, defined benefit plans] [Contrast: Increase (decrease) in net defined benefit liability (asset) resulting from interest expense (income)] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 19 -IssueDate 2023-01-01 -Paragraph 135 -Subparagraph b -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2023-en-r&anchor=para_135_b&doctype=Standard -URIDate 2023-03-23 + Details
Name: | ifrs-full_InterestExpenseDefinedBenefitPlans
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of interest income arising from defined benefit plans. [Refer: Interest income; Post-employment benefit expense in profit or loss, defined benefit plans] [Contrast: Increase (decrease) in net defined benefit liability (asset) resulting from interest expense (income)] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 19 -IssueDate 2023-01-01 -Paragraph 135 -Subparagraph b -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2023-en-r&anchor=para_135_b&doctype=Standard -URIDate 2023-03-23 + Details
Name: | ifrs-full_InterestIncomeDefinedBenefitPlans
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of post-employment benefit expense included in profit or loss relating to defined benefit plans. [Refer: Profit (loss); Defined benefit plans [member]] [Contrast: Increase (decrease) in net defined benefit liability (asset) resulting from expense (income) in profit or loss] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 19 -IssueDate 2023-01-01 -Paragraph 5 -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2023-en-r&anchor=para_5&doctype=Standard -URIDate 2023-03-23 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 19 -IssueDate 2023-01-01 -Paragraph 135 -Subparagraph b -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2023-en-r&anchor=para_135_b&doctype=Standard -URIDate 2023-03-23 + Details
Name: | ifrs-full_PostemploymentBenefitExpenseDefinedBenefitPlans
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of post-employment benefit expense relating to defined contribution plans. Defined contribution plans are post-employment benefit plans under which an entity pays fixed contributions into a separate entity (a fund) and will have no legal or constructive obligation to pay further contributions if the fund does not hold sufficient assets to pay all employee benefits relating to employee service in the current and prior periods. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2023-01-01 -Paragraph 53 -URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2023-en-r&anchor=para_53&doctype=Standard -URIDate 2023-03-23 + Details
Name: | ifrs-full_PostemploymentBenefitExpenseDefinedContributionPlans
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Administrative Expenses, Net Defined Benefit Liability (Asset) + References No definition available. + Details
Name: | tac_AdministrativeExpensesNetDefinedBenefitLiabilityAsset
Namespace Prefix: | tac_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Curtailment and Plan Amendment Gain (Loss), Net Defined Benefit Liability (Asset) + References No definition available. + Details
Name: | tac_CurtailmentandPlanAmendmentGainLossNetDefinedBenefitLiabilityAsset
Namespace Prefix: | tac_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | ifrs-full_NetDefinedBenefitLiabilityAssetAxis=ifrs-full_PresentValueOfDefinedBenefitObligationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_NetDefinedBenefitLiabilityAssetAxis=ifrs-full_PlanAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CharacteristicsOfDefinedBenefitPlansAxis=tac_RegisteredPensionPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CharacteristicsOfDefinedBenefitPlansAxis=tac_SupplementalPensionPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CharacteristicsOfDefinedBenefitPlansAxis=tac_OtherPostEmploymentBenefitPlansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |