Income Taxes - Schedule of Income tax Recovery (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Computed taxes at combined Canadian and U.S. tax rates	$ (10,095)	$ (5,997)	$ (6,561)
Change in tax rate		26
Non-deductible expenses	649	446	185
Research and development credits	(1,305)
Change in valuation allowance	10,520	5,525	4,519
Other	231
Reversal of tax benefit related to taxable preferred stock			1,685
Other impact upon conversion of taxable preferred stock			172
Income tax recovery	$ 0	$ 0	$ 0