ASSET RETIREMENT OBLIGATION (Details) - CAD CAD in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014
ASSET RETIREMENT OBLIGATION
Total undiscounted liability	CAD 556,400	CAD 730,900
Risk free rate for calculating asset retirement obligation (as a percent)	5.91%	5.92%
Period for expected payments to be incurred	65 years
Changes in asset retirement obligation
Balance, beginning of year	CAD 288,692	CAD 291,761
Change in estimates	(35,386)	4,378
Property acquisition and development activity	761	1,778
Divestments	(48,748)	(4,313)
Settlements	(14,935)	(19,409)
Accretion expense	15,975	14,497
Balance, end of year	CAD 206,359	CAD 288,692

Represents the amount of asset retirement obligation disposed of during the period through sales to third parties.

No definition available.

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- Definition

Represents the number of years over which the asset retirement obligations are expected to be incurred.

+ References

No definition available.

+ Details

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- Definition

Represents the weighted credit-adjusted risk-free interest rate used to calculate the asset retirement obligation.

+ References

No definition available.

+ Details

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- Definition

Represents the carrying amount of undiscounted liability for an asset retirement obligation.

+ References

No definition available.

+ Details

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- Definition

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Asset Retirement Obligation
-URI http://asc.fasb.org/extlink&oid=6505190

+ Details

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- Definition

Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848

+ Details

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- References

No definition available.

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- Definition

Amount of asset retirement obligations incurred during the period.

+ References

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- Definition

Amount of asset retirement obligations settled, or otherwise disposed of, during the period. This may include asset retirement obligations transferred to third parties associated with the sale of a long-lived asset.

+ References

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- Definition

Amount of the Increase or Decrease in the amount of the asset retirement obligation during the current period for changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation.

+ References

+ Details

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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