INCOME TAXES - Additional Information (Details) - CAD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
INCOME TAXES
Amount reclassified	$ 13.9	$ 27.2

The amount reclassified from deferred income tax asset to income tax receivable for the AMT credit carryover refund expected to be realized in the next year.

No definition available.

Name:	erf_ReclassificationDeferredTaxAssetToIncomeTaxReceivableAtm
Namespace Prefix:	erf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant