Share Capital - Stock Option Activity (Details) - shares		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Options Outstanding, Beginning balance		2,663,788	2,831,985	2,671,906	2,339,905
Number of Options, Granted		1,180,175	12,000	1,202,075	698,450
Number of Options, Exercised	[1]	(148,948)	(119,129)	(174,811)	(237,848)
Number of Options, Forfeited, cancelled or expired		(43,096)	(42,593)	(47,251)	(118,244)
Number of Options Outstanding, Ending balance		3,651,919	2,682,263	3,651,919	2,682,263
Number of Options Exercisable, End of period		1,846,826	1,471,329	1,846,826	1,471,329

[1] During the nine months ended September 30, 2019, 23,625 stock options were exercised for the same number of common shares for cash (nine months ended September 30, 2018 – 41,507). In the same period, the Company issued 94,248 common shares (nine months ended September 30, 2018 – 103,189) for the cashless exercise of 151,186 stock options (nine months ended September 30, 2018 – 196,341).