SHAREHOLDERS' EQUITY - Paid-in Capital (Details) - CAD CAD in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Paid-in Capital activity
Balance, beginning of year	CAD 46,906	CAD 38,398	CAD 32,293
Share-based compensation - settled	(10,050)
Stock Option Plan - exercised	(267)	(4,978)	(3,108)
Share-based compensation - non-cash	19,587	13,486	9,213
Balance, end of year	CAD 56,176	CAD 46,906	CAD 38,398

This element represents the amount of recognized equity-based compensation related to equity-settled RSUs and PSUs and stock options during the period, that is, the amount recognized as expense in the income statement (or as asset if compensation is capitalized).

No definition available.

+ Details

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Namespace Prefix:	erf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the non cash fair value expense related to the shares issued during the period under the Stock Option Plan.

+ References

No definition available.

+ Details

Name:	erf_StockIssuedDuringPeriodValueStockOptionPlanNoncash
Namespace Prefix:	erf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Value received from shareholders in common stock-related transactions that are in excess of par value or stated value and amounts received from other stock-related transactions. Includes only common stock transactions (excludes preferred stock transactions). May be called contributed capital, capital in excess of par, capital surplus, or paid-in capital.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.30(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 31
-Article 5

+ Details

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Period Type:	instant

- References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Changes in additional paid in capital related to exercise of share-based payments awards (such as stock options) and the amount of recognized equity-based compensation during the period (such as nonvested shares).

+ References

No definition available.

+ Details

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