XML 173 R109.htm IDEA: XBRL DOCUMENT
v3.20.4

Pension and other post-retirement benefits - Assumptions and 1% change (Details) - CAD ($) | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019
Pension plans [member] |  |
Assumptions defined benefit obligation and net pension and other benefit expense |  |
Discount rate - obligation | 2.40% | 3.00%
Discount rate - expense | 3.00% | 3.70%
Rate of compensation increase | 2.90% | 3.00%
Pension plans [member] | Discount rate [member] |  |
Sensitivity analysis of actuarial assumptions |  |
Increase in actuarial assumption by | 1.00% |
Increase in defined benefit obligation | $ 12,766,000 |
Decrease in actuarial assumption by | 1.00% |
Decrease in defined benefit obligation | $ (9,778,000) |
Pension plans [member] | Rate of compensation increase [member] |  |
Sensitivity analysis of actuarial assumptions |  |
Increase in actuarial assumption by | 1.00% |
Increase in defined benefit obligation | $ 3,009,000 |
Decrease in actuarial assumption by | 1.00% |
Decrease in defined benefit obligation | $ (2,772,000) |
Pension plans [member] | Increase of one year in the expected lifetime [member] |  |
Sensitivity analysis of actuarial assumptions |  |
Increase in defined benefit obligation | $ 2,030,000 |
Other Benefit Plans [Member] |  |
Assumptions defined benefit obligation and net pension and other benefit expense |  |
Discount rate - obligation | 2.50% | 3.10%
Discount rate - expense | 3.10% | 3.90%
Initial health care cost trend rate | 5.00% | 6.00%
Cost trend rate declines to | 5.00% | 5.00%
Year the rate reaches its final level | 2021 | 2022
Dental care cost trend rate | 4.50% | 5.00%
Other Benefit Plans [Member] | Discount rate [member] |  |
Sensitivity analysis of actuarial assumptions |  |
Increase in actuarial assumption by | 1.00% |
Increase in defined benefit obligation | $ 4,138,000 |
Decrease in actuarial assumption by | 1.00% |
Decrease in defined benefit obligation | $ (3,270,000) |

X
- Definition Declining cost rate related to medical costs used as significant actuarial assumption to determine the present value of a defined benefit obligation. + References No definition available. + Details
Name: | ccj_ActuarialAssumptionOfDecliningMedicalCostTrendRate
Namespace Prefix: | ccj_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Dental cost trend rate used as significant actuarial assumption to determine the present value of a defined benefit obligation. + References No definition available. + Details
Name: | ccj_ActuarialAssumptionOfDentalCostTrendRates
Namespace Prefix: | ccj_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The discount rate used as the significant actuarial assumption to determine the present value of a defined benefit expense. + References No definition available. + Details
Name: | ccj_ActuarialAssumptionOfDiscountRatesPriorYearObligations
Namespace Prefix: | ccj_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The year in which the rate reaches its final level, in CCYY format. + References No definition available. + Details
Name: | ccj_ActuarialAssumptionOfYearRateReachesFinalLevel
Namespace Prefix: | ccj_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | ccj_AssumptionsDefinedBenefitObligationNetPensionOtherBenefitExpenseAbstract
Namespace Prefix: | ccj_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The discount rate used as the significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit obligation, at present value; Actuarial assumptions [member]] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 19 -IssueDate 2020-01-01 -Paragraph 144 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2020-en-r&anchor=para_144&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_ActuarialAssumptionOfDiscountRates
Namespace Prefix: | ifrs-full_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The expected rate of salary increases used as a significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit plans [member]; Defined benefit obligation, at present value; Actuarial assumptions [member]] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 19 -IssueDate 2020-01-01 -Paragraph 144 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2020-en-r&anchor=para_144&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_ActuarialAssumptionOfExpectedRatesOfSalaryIncreases
Namespace Prefix: | ifrs-full_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Medical cost trend rate used as significant actuarial assumption to determine the present value of a defined benefit obligation. [Refer: Defined benefit obligation, at present value; Actuarial assumptions [member]] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 19 -IssueDate 2020-01-01 -Paragraph 144 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2020-en-r&anchor=para_144&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_ActuarialAssumptionOfMedicalCostTrendRates
Namespace Prefix: | ifrs-full_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- References No definition available. + Details
Name: | ifrs-full_DisclosureOfSensitivityAnalysisForActuarialAssumptionsAbstract
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The increase (decrease) in a defined benefit obligation that would have been caused by a decrease in a significant actuarial assumption that was reasonably possible at the end of the reporting period. [Refer: Actuarial assumptions [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2020-01-01 -Paragraph 145 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2020-en-r&anchor=para_145_a&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_IncreaseDecreaseInDefinedBenefitObligationDueToReasonablyPossibleDecreaseInActuarialAssumption
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The increase (decrease) in a defined benefit obligation that would have been caused by an increase in a significant actuarial assumption that was reasonably possible at the end of the reporting period. [Refer: Actuarial assumptions [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2020-01-01 -Paragraph 145 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2020-en-r&anchor=para_145_a&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_IncreaseDecreaseInDefinedBenefitObligationDueToReasonablyPossibleIncreaseInActuarialAssumption
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The reasonably possible percentage of the decrease in the actuarial assumption used to determine the present value of defined benefit obligation. [Refer: Actuarial assumptions [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2020-01-01 -Paragraph 145 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2020-en-r&anchor=para_145_a&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_PercentageOfReasonablyPossibleDecreaseInActuarialAssumption
Namespace Prefix: | ifrs-full_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The reasonably possible percentage of the increase in the actuarial assumption used to determine the present value of defined benefit obligation. [Refer: Actuarial assumptions [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2020-01-01 -Paragraph 145 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2020-en-r&anchor=para_145_a&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_PercentageOfReasonablyPossibleIncreaseInActuarialAssumption
Namespace Prefix: | ifrs-full_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | ifrs-full_DefinedBenefitPlansAxis=ifrs-full_PensionDefinedBenefitPlansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ActuarialAssumptionsAxis=ifrs-full_ActuarialAssumptionOfDiscountRatesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ActuarialAssumptionsAxis=ifrs-full_ActuarialAssumptionOfExpectedRatesOfSalaryIncreasesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ActuarialAssumptionsAxis=ifrs-full_ActuarialAssumptionOfLifeExpectancyAfterRetirementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_DefinedBenefitPlansAxis=ccj_OtherBenefitPlansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |