Note 13 - Provisions (Details Textual)	Jun. 30, 2019
Statement Line Items [Line Items]
Restructuring, number of positions eliminated	200

The number of positions eliminated during the period as a result of restructuring activities.

No definition available.

Name:	je_RestructuringNumberOfPositionsEliminated
Namespace Prefix:	je_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant