XML 118 R90.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Significant Events - TransAlta Renewables Acquires Three Renewable Assets from the Corporation (Details) $ in Millions |  |  | 12 Months Ended |
--- | --- | --- | --- | ---
Jun. 28, 2018 CAD ($) | May 31, 2018 CAD ($) MW | Dec. 31, 2018 CAD ($) | Nov. 30, 2016 CAD ($)
Investment [Line Items] |  |  |  |
Consideration received |  |  | $ 10 |
Transfer of equity from non-controlling interests |  |  | $ 1 | $ 38
Issued preferred capital | $ 33 |  |  |
Lakeswind |  |  |  |
Investment [Line Items] |  |  |  |
Impairment loss | 12 |  |  |
TransAlta Renewables | Lakeswind Wind Farm |  |  |  |
Investment [Line Items] |  |  |  |
Capacity of facility (in megawatts) | MW |  | 50 |  |
TransAlta Renewables | Lakeswind Solar Projects |  |  |  |
Investment [Line Items] |  |  |  |
Capacity of facility (in megawatts) | MW |  | 21 |  |
TransAlta Renewables | Kent Breeze |  |  |  |
Investment [Line Items] |  |  |  |
Capacity of facility (in megawatts) | MW |  | 20 |  |
TransAlta Renewables | Three Renewable Assets |  |  |  |
Investment [Line Items] |  |  |  |
Consideration received |  | $ 166 |  |
Value of equity consideration received |  | 62 |  |
Portion of consideration paid (received) consisting of cash and cash equivalents |  | $ 104 |  |
Property, plant, and equipment | Lakeswind |  |  |  |
Investment [Line Items] |  |  |  |
Impairment loss | 11 |  |  |
Intangible assets | Lakeswind |  |  |  |
Investment [Line Items] |  |  |  |
Impairment loss | $ 1 |  |  |

X
- Definition The amount of consideration paid or received in respect of both obtaining and losing control of subsidiaries or other businesses. [Refer: Subsidiaries [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 7 -IssueDate 2017-01-01 -Paragraph 40 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=7&date=2017-03-01&anchor=para_40_a&doctype=Standard -URIDate 2017-03-09 + Details
Name: | ifrs-full_ConsiderationPaidReceived
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount recognised as a reduction of the carrying amount of an asset or cash-generating unit to its recoverable amount. [Refer: Carrying amount [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2017-01-01 -Paragraph 130 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2017-03-01&anchor=para_130_b&doctype=Standard -URIDate 2017-03-09 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2017-01-01 -Paragraph 130 -Subparagraph d -Clause ii -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2017-03-01&anchor=para_130_d_ii&doctype=Standard -URIDate 2017-03-09 + Details
Name: | ifrs-full_ImpairmentLoss
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The portion of consideration paid or received, consisting of cash and cash equivalents, in respect of both obtaining and losing control of subsidiaries or other businesses. [Refer: Subsidiaries [member]; Cash and cash equivalents; Consideration paid (received)] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 7 -IssueDate 2017-01-01 -Paragraph 40 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=7&date=2017-03-01&anchor=para_40_b&doctype=Standard -URIDate 2017-03-09 + Details
Name: | ifrs-full_PortionOfConsiderationPaidReceivedConsistingOfCashAndCashEquivalents
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Line items represent reporting concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 12 -Sentence Column A + Details
Name: | invest_InvestmentLineItems
Namespace Prefix: | invest_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Capacity Of Generation Units, Power + References No definition available. + Details
Name: | tac_CapacityOfPowerGenerationAssetsPower
Namespace Prefix: | tac_
Data Type: | num:powerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Issued Preferred Capital + References No definition available. + Details
Name: | tac_IssuedPreferredCapital
Namespace Prefix: | tac_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Portion Of Consideration Paid (Received) Consisting Of Equity Interests + References No definition available. + Details
Name: | tac_PortionOfConsiderationPaidReceivedConsistingOfEquityInterests
Namespace Prefix: | tac_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Transfer Of Equity From Non-Controlling Interests + References No definition available. + Details
Name: | tac_TransferOfEquityFromNonControllingInterests
Namespace Prefix: | tac_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | ifrs-full_TypesOfInvestmentPropertyAxis=tac_LakeswindMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CounterpartiesAxis=tac_TransAltaRenewablesInc.Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfInvestmentPropertyAxis=tac_LakeswindWindFarmMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfInvestmentPropertyAxis=tac_LakeswindSolarProjectsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfInvestmentPropertyAxis=tac_KentBreezeWindFarmMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfInvestmentPropertyAxis=tac_ThreeRenewableAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=tac_PropertyPlantsAndEquipmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfPropertyPlantAndEquipmentAxis=ifrs-full_OtherPropertyPlantAndEquipmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |