Note 24 - Earnings Per Share (Details Textual) - shares	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement Line Items [Line Items]
Antidilutive options excluded from computation of earnings per share, amount	37,302	18,378	68,795
Options out of the money [member]
Statement Line Items [Line Items]
Antidilutive options excluded from computation of earnings per share, amount	20,000	5,000

Number of options that could potentially dilute basic earnings per share in the future that were not included in the computation of diluted earnings per share because to do so would increase or decrease earnings per share for the periods presented.

No definition available.

Name:	cmcl_AntidilutiveOptionsExcludedFromComputationOfEarningsPerShareAmount
Namespace Prefix:	cmcl_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration