INVENTORIES - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Inventory Disclosure [Abstract]
Impairment loss	$ 0	$ 1,640

Impairment Loss Related to Concentrations and Work-in-Progress Inventory

No definition available.

Name:	efr_ImpairmentLossRelatedtoConcentrationsandWorkinProgressInventory
Namespace Prefix:	efr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration