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Share Capital (Stock Options) (Details) | 12 Months Ended
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Dec. 31, 2019 shares $ / shares | Dec. 31, 2018 shares $ / shares
Disclosure of share capital, reserves and other equity interest [Abstract] |  |
Number of options outstanding | shares | 6,655,455 | 10,429,345
Granted | shares | 965,876 | 1,009,100
Exercised | shares | (1,555,989) | (1,984,698)
Expired | shares | (1,600,080) | (2,798,292)
Number of options outstanding | shares | 4,465,262 | 6,655,455
Beginning balance, Weighted average exercise price (cad per share) | $ 7.38 | $ 7.94
Granted (cad per share) | 6.59 | 6.56
Exercised (cad per share) | 5.93 | 2.40
Expired (cad per share) | 10.52 | 12.70
Ending balance, Weighted average exercise price (cad per share) | 6.59 | 7.38
Exercise price of outstanding share options | $ 9.66 | $ 5.89

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