Share Capital (Tables)

9 Months Ended

Sep. 30, 2020

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,
	2020			2019			2020			2019
Outstanding, beginning of period		4,595,432			2,663,788			3,534,236			2,671,906
Granted		194,400			1,180,175			1,440,050			1,202,075
Exercised(1)		(375	)		(148,948	)		(153,417	)		(174,811	)
Forfeited, cancelled or expired		(3,363	)		(43,096	)		(34,775	)		(47,251	)
Outstanding, end of period		4,786,094			3,651,919			4,786,094			3,651,919
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).}

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,
	2020			2019			2020			2019
Average risk-free interest rate		0.40	%		1.76	%		0.72	%		1.77	%
Expected volatility		68	%		69	%		68	%		69	%
Average expected term (in years)		6.64			7.04			6.79			7.03
Expected dividend yield		0	%		0	%		0	%		0	%
Weighted average fair value of stock options granted	$	7.03		$	6.24		$	7.46		$	6.22