Share Capital - Stock Option Activity (Details) - shares		3 Months Ended		12 Months Ended
		Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Outstanding, beginning of period		1,910,823	1,721,472	1,721,472
Granted		416,750	233,950
Exercised	[1]	(67,921)	(16,246)
Forfeited and expired		(1,415)	(4,442)
Outstanding, end of period		2,258,237	1,934,734	1,910,823
Exercisable, end of period		1,293,367	1,151,853

[1] During the three months ended March 31, 2017, 62,397 stock options were exercised for the same number of common shares for cash (three months ended March 31, 2016 – 16,246). In the same period, the Company issued 3,693 common shares (three months ended March 31, 2016 – nil) for the cashless exercise of 5,524 stock options (three months ended March 31, 2016 – nil).