XML 157 R93.htm IDEA: XBRL DOCUMENT
v3.20.4

Income Taxes - Significant components of unrecognized deferred tax assets (Details) - CAD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Disclosure of temporary difference, unused tax losses and unused tax credits [line items] |  |
Unrecognized deferred tax assets | $ 408,809 | $ 428,113
Income tax losses (gains) [member] |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [line items] |  |
Unrecognized deferred tax assets | 271,163 | 280,330
Property, plant and equipment, deferred tax assets [Member] |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [line items] |  |
Unrecognized deferred tax assets | 2,204 | 2,321
Provision for reclamation [member] |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [line items] |  |
Unrecognized deferred tax assets | 75,219 | 75,082
Long-term investments and other, deferred tax assets [member] |  |
Disclosure of temporary difference, unused tax losses and unused tax credits [line items] |  |
Unrecognized deferred tax assets | $ 60,223 | $ 70,380

X
- Definition The amount of deductible temporary differences for which no deferred tax asset is recognised in the statement of financial position. [Refer: Temporary differences [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 12 -IssueDate 2020-01-01 -Paragraph 81 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=12&code=ifrs-tx-2020-en-r&anchor=para_81_e&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_DeductibleTemporaryDifferencesForWhichNoDeferredTaxAssetIsRecognised
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

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

X
- Details
Name: | ifrs-full_TemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsAxis=ifrs-full_UnusedTaxLossesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsAxis=ccj_DeferredTaxAssetsPropertyPlantAndEquipmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsAxis=ccj_DeferredTaxAssetsProvisionForReclamationtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TemporaryDifferenceUnusedTaxLossesAndUnusedTaxCreditsAxis=ccj_DeferredTaxAssetsLongTermInvestmentAndOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |