Summary of significant accounting policies - Financial instruments (Details)	12 Months Ended
Dec. 31, 2019
Summary of significant accounting policies
Period for which the company used historic credit loss experience	2 years
Percentage of forward-looking factor	10.00%
Default period	90 days

Represents the percentage of forward looking factor used as a adjustment to calculate allowance for expected credit losses using historical credit loss experience.

No definition available.

Name:	jmia_PercentageOfForwardLookingFactor
Namespace Prefix:	jmia_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration