Share Capital (Tables)

9 Months Ended

Sep. 30, 2019

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock Option Activity

The following table presents stock option activity for the period:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2019			2018			2019			2018
Outstanding, beginning of period		2,663,788			2,831,985			2,671,906			2,339,905
Granted		1,180,175			12,000			1,202,075			698,450
Exercised(1)		(148,948	)		(119,129	)		(174,811	)		(237,848	)
Forfeited, cancelled or expired		(43,096	)		(42,593	)		(47,251	)		(118,244	)
Outstanding, end of period		3,651,919			2,682,263			3,651,919			2,682,263
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).

Fair Value Assumptions for Stock Options

The fair value of each stock option granted is estimated using the Black-Scholes option-pricing model with the following weighted-average assumptions:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2019			2018			2019			2018
Average risk-free interest rate		1.76	%		2.81	%		1.77	%		2.79	%
Expected volatility		69	%		76	%		69	%		75	%
Average expected term (in years)		7.04			6.27			7.03			7.39
Expected dividend yield		0	%		0	%		0	%		0	%
Weighted average fair value of stock optionsgranted	$	6.24		$	8.75		$	6.22		$	3.70