| In millions, except per share items | Dec-31-22 | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| OIL SALES (NOTE 11) | 711.4 | 473.7 | 237.8 | 571.0 | 613.4 | 421.7 | -3.9 | 276.0 |
| OIL SALES (NOTE 11) growth | 50.2% | 99.2% | -58.3% | -6.9% | 45.5% | -10844.8% | -101.4% | -50.1% |
| EXPENSES | | | | | | | | |
| Operating | 162.4 | 135.7 | 114.4 | 183.2 | 111.3 | 87.9 | 64.2 | 75.6 |
| Transportation | 10.2 | 11.6 | 10.7 | 20.4 | 29.0 | 25.1 | 31.8 | 40.2 |
| Depletion, depreciation and accretion (Note 5 and 10) | 180.3 | 139.9 | 164.2 | 225.0 | 197.9 | 131.3 | | |
| Goodwill impairment (Note 6) | | | 102.6 | | | | | |
| Asset impairment (Note 6) | | | 1,227.4 | | | 1.5 | 616.6 | 323.9 |
| General and administrative | 41.0 | 36.3 | 25.4 | 36.5 | 39.5 | 39.0 | 33.2 | 32.4 |
| Foreign exchange loss | 2.6 | 20.5 | 4.2 | 0.6 | 10.0 | 2.1 | -1.5 | -17.2 |
| Derivative instruments loss (Note 14) | 26.6 | 48.8 | 2.9 | 3.7 | | | | |
| Other financial instruments (gain) loss (Note 14) | 26.6 | 52.2 | 48.0 | -49.9 | | | | |
| Interest expense (Note 8) | 46.5 | 54.4 | 54.1 | 43.3 | -27.4 | -13.9 | -14.1 | |
| TOTAL EXPENSES | 469.5 | 450.5 | 2,458.2 | 462.8 | 464.0 | 341.2 | -942.8 | 645.5 |
| OTHER GAIN (LOSS) | 2.6 | 0.0 | -0.5 | | | | | |
| INTEREST INCOME | 0.4 | | 0.3 | | | | 2.4 | |
| |
| INCOME TAX EXPENSE (RECOVERY) | | | | | | | | |
| Current (Note 12) | 80.6 | 4.5 | 0.8 | 17.1 | 43.9 | 24.3 | 20.1 | -15.4 |
| Deferred (Note 12) | 25.3 | -23.8 | -76.1 | 40.2 | 5.0 | 44.7 | -204.8 | 115.4 |
| Total income tax expense (recovery) | 105.9 | -19.3 | -75.4 | 57.3 | 48.9 | 69.0 | -184.7 | |
| NET AND COMPREHENSIVE INCOME (LOSS) | 139.0 | 42.5 | -778.0 | 38.7 | 102.6 | -31.7 | -465.6 | -268.0 |
| |
| NET INCOME (LOSS) PER SHARE | | | | | | | | |
| Basic (in dollars per share) | $0.38 | $0.12 | ($2.12) | $0.10 | $0.26 | ($0.08) | ($1.45) | ($0.94) |
| Diluted (in dollars per share) | $0.38 | $0.12 | ($2.12) | $0.10 | $0.26 | ($0.08) | ($1.45) | ($0.94) |
| |
| Weighted average shares outstanding - basic (in shares) | 364.5 | 367.0 | 367.0 | 376.5 | 390.9 | 396.7 | 320.9 | 285.3 |
| Weighted average shares outstanding - diluted (in shares) | 369.3 | 367.9 | 367.0 | 376.5 | 427.1 | 396.7 | 320.9 | 285.3 |