Share Capital - Stock Option Activity (Details) - shares		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Options Outstanding, Beginning balance		4,595,432	2,663,788	3,534,236	2,671,906
Number of Options, Granted		194,400	1,180,175	1,440,050	1,202,075
Number of Options, Exercised	[1]	(375)	(148,948)	(153,417)	(174,811)
Number of Options, Forfeited, cancelled or expired		(3,363)	(43,096)	(34,775)	(47,251)
Number of Options Outstanding, Ending balance		4,786,094	3,651,919	4,786,094	3,651,919
Number of Options Exercisable, End of period		2,324,090	1,846,826	2,324,090	1,846,826

[1] During the nine months ended September 30, 2020, 10,715 stock options were exercised for the same number of common shares for cash (nine months ended September 30, 2019 – 23,625). In the same period, the Company issued 85,816 common shares (nine months ended September 30, 2019 – 94,248) for the cashless exercise of 142,702 stock options (nine months ended September 30, 2019 – 151,186).