Note 28 - Provisions (Details Textual) - Provision for decommissioning, restoration and rehabilitation costs for Blanket mine [member] - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement Line Items [Line Items]
Major assumptions made concerning future events, other provisions, discount rate	1.45%	2.31%	2.95%
Major assumptions made concerning future events, other Provisions, inflation rate	2.05%	2.27%	2.13%
Other provisions, undiscounted cash flows	$ 3,389	$ 3,364	$ 3,604

The assumed inflation rate for the uncertainties relating to the amount or timing of outflows of economic benefits for other provisions.

No definition available.

Name:	cmcl_MajorAssumptionsMadeConcerningFutureEventsOtherProvisionsInflationRate
Namespace Prefix:	cmcl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant