| Year ended December 31 | |||||||||
| 2017 | 2016 | 2015 | |||||||
| $ | $ | $ | |||||||
| Exploration and Evaluation Assets (E & E assets) | |||||||||
| Impairment losses (Note 5) | 971 | 1,790 | 534 | ||||||
| Property and Equipment (D & P assets) | |||||||||
| Amortization and depletion (Note 6) | 787 | 1,633 | 2,655 | ||||||
| Impairment losses (Note 6) | 870 | 1,070 | 1,000 | ||||||
| 2,628 | 4,493 | 4,189 | |||||||