XML 129 R99.htm IDEA: XBRL DOCUMENT v3.25.0.1

Investments - Change in Investments (Details) - CAD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Change In Investments [Roll Forward]
Equity (loss) income	$ 5	$ 4	$ 9
EMG | Equity-accounted
Change In Investments [Roll Forward]
Beginning balance	8	12
Investment	0	0
Equity (loss) income	(4)	(4)
Distributions received	0	0
Change in foreign exchange rates	2	0
Net change in fair value recognized in earnings	0
Ending balance	6	8	12
Skookumchuck | Equity-accounted
Change In Investments [Roll Forward]
Beginning balance	104	105
Investment	0	0
Equity (loss) income	10	8
Distributions received	(5)	(6)
Change in foreign exchange rates	9	(3)
Net change in fair value recognized in earnings	0
Ending balance	118	104	105
Tent Mountain | Equity-accounted
Change In Investments [Roll Forward]
Beginning balance	10	0
Investment	3	10
Equity (loss) income	(1)	0
Distributions received	0	0
Change in foreign exchange rates	0	0
Net change in fair value recognized in earnings	0
Ending balance	12	10	0
EIP | FVTPL
Change In Investments [Roll Forward]
Beginning balance	15	11
Investment	5	4
Equity (loss) income	0	0
Distributions received	0	0
Change in foreign exchange rates	0	0
Net change in fair value recognized in earnings	2
Ending balance	22	15	11
Ekona | FVTOCI
Change In Investments [Roll Forward]
Beginning balance	1	1
Investment	0	0
Equity (loss) income	0	0
Distributions received	0	0
Change in foreign exchange rates	0	0
Net change in fair value recognized in earnings	0
Ending balance	1	1	1
Total for all consolidated structured entities
Change In Investments [Roll Forward]
Beginning balance	138	129
Investment	8	14
Equity (loss) income	5	4	9
Distributions received	(5)	(6)
Change in foreign exchange rates	11	(3)
Net change in fair value recognized in earnings	2
Ending balance	$ 159	$ 138	$ 129

X

- Definition

The cash inflow representing dividends received from investments that are accounted for using the equity method, classified as investing activities. [Refer: Investments accounted for using equity method; Dividends received]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 7
-IssueDate 2024-01-01
-Paragraph 16
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2024-en-r&anchor=para_16&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_DividendsReceivedFromInvestmentsAccountedForUsingEquityMethodClassifiedAsInvestingActivities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

The amount of investments in equity instruments that the entity has designated at fair value through other comprehensive income. [Refer: At fair value [member]; Other comprehensive income]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2024-01-01
-Paragraph 11A
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2024-en-r&anchor=para_11A_c&doctype=Standard
-URIDate 2024-03-27

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2024-01-01
-Paragraph 8
-Subparagraph h
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2024-en-r&anchor=para_8_h&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_FairValueOfInvestmentsInEquityInstrumentsDesignatedAsMeasuredAtFairValueThroughOtherComprehensiveIncome
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

The increase (decrease) in financial assets resulting from foreign exchange. [Refer: Financial assets]

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 7
-IssueDate 2024-01-01
-Paragraph IG20B
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2024-en-r&anchor=para_IG20B&doctype=Implementation%20Guidance
-URIDate 2024-03-27

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 7
-IssueDate 2024-01-01
-Paragraph 35H
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2024-en-r&anchor=para_35H&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_IncreaseDecreaseThroughForeignExchangeFinancialAssets
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

The amount of investments in associates accounted for using the equity method. [Refer: Total for all associates [member]; Investments accounted for using equity method]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2024-01-01
-Paragraph 55
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_55&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_InvestmentsInAssociatesAccountedForUsingEquityMethod
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

The cash outflow to acquire interests in joint ventures (other than payments for those instruments considered to be cash equivalents or those held for dealing or trading purposes), classified as investing activities. [Refer: Total for all joint ventures [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 7
-IssueDate 2024-01-01
-Paragraph 16
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2024-en-r&anchor=para_16_c&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_OtherCashPaymentsToAcquireInterestsInJointVenturesClassifiedAsInvestingActivities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

The entity's share of the profit (loss) of associates accounted for using the equity method. [Refer: Total for all associates [member]; Investments accounted for using equity method; Profit (loss)]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2024-01-01
-Paragraph 85
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2024-en-r&anchor=para_85&doctype=Standard
-URIDate 2024-03-27

+ Details

Name:	ifrs-full_ShareOfProfitLossOfAssociatesAccountedForUsingEquityMethod
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Change In Investments

+ References

No definition available.

+ Details

Name:	tac_ChangeInInvestmentsRollForward
Namespace Prefix:	tac_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	ifrs-full_JointVenturesAxis=tac_EMGInternationalLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialAssetsAxis=ifrs-full_EquityInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_JointVenturesAxis=tac_SkookumchuckWindEnergyProjectLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_JointVenturesAxis=tac_TentMountainPumpedHydroDevelopmentProjectMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_JointVenturesAxis=tac_EnergyImpactPartnersInvestmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialAssetsAxis=ifrs-full_FinancialAssetsAtFairValueThroughProfitOrLossCategoryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_JointVenturesAxis=tac_EkonaPowerIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ClassesOfFinancialAssetsAxis=ifrs-full_InvestmentsInEquityInstrumentsMeasuredAtFairValueThroughOtherComprehensiveIncomeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ifrs-full_ConsolidatedStructuredEntitiesAxis=ifrs-full_ConsolidatedStructuredEntitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: