Share Capital (Tables)

6 Months Ended

Jun. 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 June 30,						Six Months Ended June 30,
	2020			2019			2020			2019
Outstanding, beginning of period		4,527,992			2,667,449			3,534,236			2,671,906
Granted		127,300			—			1,245,650			21,900
Exercised(1)		(54,716	)		(3,461	)		(153,042	)		(25,863	)
Forfeited, cancelled or expired		(5,144	)		(200	)		(31,412	)		(4,155	)
Outstanding, end of period		4,595,432			2,663,788			4,595,432			2,663,788
Exercisable, end of period		2,114,647			1,913,129			2,114,647			1,913,129

^{(1) During the six months ended June 30, 2020, 10,715 stock options were exercised for the same number of common shares for cash (six months ended June 30, 2019 – 23,472). In the same period, the Company issued 85,660 common shares (six months ended June 30, 2019 – 863) for the cashless exercise of 142,327 stock options (six months ended June 30, 2019 – 2,391).}

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 June 30,				Six Months Ended June 30,
	2020			2019 (1)	2020			2019
Average risk-free interest rate		0.48	%	N/A		0.77	%		2.58	%
Expected volatility		68	%	N/A		68	%		76	%
Average expected term (in years)		6.86		N/A		6.75			6.27
Expected dividend yield		0	%	N/A		0	%		0	%
Weighted average fair value of stock options granted	$	8.27		N/A	$	7.50		$	5.34

^{(1) No stock options were granted during the three months ended June 30, 2019.}