XML 104 R40.htm IDEA: XBRL DOCUMENT
v3.20.4

Significant accounting policies (Table) | 12 Months Ended
--- | ---
Dec. 31, 2020
Significant Accounting Policies [Abstract] |
Basis of presentation |
Derivative financial instruments | Fair value through profit or loss (FVTPL)
Equity investments | Fair value through other comprehensive income
|  |  | (FVOCI)
Liabilities for cash-settled share-based payment arrangements | FVTPL
Net defined benefit liability | Fair value of plan assets less the present value of the
|  |  | defined benefit obligation
Disclosure of estimated useful lives |
Land | Not depreciated
Buildings | 15 - 25 years
Plant and equipment | 3 - 15 years
Furniture and fixtures | 3 - 10 years
Other | 3 - 5 years

X
- Definition Disclsoure of alternative basis measurement of consolidated financial statement. + References No definition available. + Details
Name: | ccj_DisclsoureOfAlternativeBasisMeasurementOfConsolidatedFinancialStatementTableTextBlock
Namespace Prefix: | ccj_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition The disclosure of depreciation and amortisation expense. [Refer: Depreciation and amortisation expense] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 10 -Subparagraph e -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_10_e&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_DisclosureOfDepreciationAndAmortisationExpenseExplanatory
Namespace Prefix: | ifrs-full_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration