Consolidated Statements of Operations - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
OIL SALES (NOTE 11)	$ 473,722,000	$ 237,838,000	$ 570,983,000
EXPENSES
Operating	132,331,000	111,888,000	183,204,000
Transportation	11,315,000	10,543,000	20,400,000
COVID-19 related costs (Note 12)	3,694,000	2,679,000	0
Depletion, depreciation and accretion (Note 5 and 10)	139,874,000	164,233,000	225,033,000
Goodwill impairment (Note 6)	0	102,581,000	0
Asset impairment (Note 6)	0	564,495,000	0
General and administrative	36,263,000	25,350,000	36,501,000
Foreign exchange loss	20,477,000	4,184,000	627,000
Derivative instruments loss (Note 15)	48,838,000	2,935,000	3,669,000
Other financial instruments loss (gain) (Note 15)	3,369,000	48,047,000	(49,884,000)
Interest expense (Note 8)	54,381,000	54,140,000	43,268,000
TOTAL EXPENSES	450,542,000	1,091,075,000	462,818,000
OTHER LOSS	(44,000)	(469,000)	(12,886,000)
INTEREST INCOME	0	345,000	696,000
INCOME (LOSS) BEFORE INCOME TAXES	23,136,000	(853,361,000)	95,975,000
INCOME TAX EXPENSE (RECOVERY)
Current (Note 13)	4,479,000	754,000	17,058,000
Deferred (Note 13)	(23,825,000)	(76,148,000)	40,227,000
INCOME TAX EXPENSE (RECOVERY)	(19,346,000)	(75,394,000)	57,285,000
NET AND COMPREHENSIVE INCOME (LOSS)	$ 42,482,000	$ (777,967,000)	$ 38,690,000
NET INCOME (LOSS) PER SHARE - BASIC (in USD per share)	$ 0.12	$ (2.12)	$ 0.10
NET INCOME (LOSS) PER SHARE - DILUTED (in USD per share)	$ 0.12	$ (2.12)	$ 0.10
WEIGHTED AVERAGE SHARES OUTSTANDING - BASIC (Note 9) (in shares)	367,022,903	366,981,556	376,495,306
WEIGHTED AVERAGE SHARES OUTSTANDING - DILUTED (Note 9) (in shares)	367,873,389	366,981,556	376,507,812