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SUPPLEMENTARY OIL & GAS INFORMATION (Unaudited) - Twelve Month Average Benchmark Prices (Details)	12 Months Ended
	Dec. 31, 2018 $ / bbl $ / MMBTU $ / bbl $ / MMBTU
Crude Oil and NGLs | WTI Cushing Oklahoma
Oil And Gas, Average Sale Price And Production Cost Per Unit1 [Line Items]
Twelve month average benchmark price dollars per bbl	65.55
Crude Oil and NGLs | WCS
Oil And Gas, Average Sale Price And Production Cost Per Unit1 [Line Items]
Twelve month average benchmark price dollars per bbl	53.67
Crude Oil and NGLs | Canadian Light Sweet
Oil And Gas, Average Sale Price And Production Cost Per Unit1 [Line Items]
Twelve month average benchmark price dollars per bbl	70.32
Crude Oil and NGLs | Cromer LSB
Oil And Gas, Average Sale Price And Production Cost Per Unit1 [Line Items]
Twelve month average benchmark price dollars per bbl	75.54
Crude Oil and NGLs | North Sea Brent
Oil And Gas, Average Sale Price And Production Cost Per Unit1 [Line Items]
Twelve month average benchmark price dollars per bbl	72.09
Crude Oil and NGLs | Edmonton C5
Oil And Gas, Average Sale Price And Production Cost Per Unit1 [Line Items]
Twelve month average benchmark price dollars per bbl	80.65
Natural Gas | Henry Hub Louisiana
Oil And Gas, Average Sale Price And Production Cost Per Unit1 [Line Items]
Twelve month average benchmark price dollars per MMBtu | $ / MMBTU	3.02
Natural Gas | AECO
Oil And Gas, Average Sale Price And Production Cost Per Unit1 [Line Items]
Twelve month average benchmark price dollars per MMBtu | $ / MMBTU	1.46
Natural Gas | BC Westcoast Station 2
Oil And Gas, Average Sale Price And Production Cost Per Unit1 [Line Items]
Twelve month average benchmark price dollars per MMBtu | $ / MMBTU	1.25
USD
Oil And Gas, Average Sale Price And Production Cost Per Unit1 [Line Items]
Average foreign exchange rate	1.00

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The average exchange rate used by the entity. Exchange rate is the ratio of exchange for two currencies.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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-IssueDate 2018-01-01
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