Income Taxes - Reconciliation of Income Tax Provision Computed at Statutory Rates (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Statutory tax rate	34.00%	34.00%
Net loss before income taxes	$ 12,040	$ 28,024
Expected income tax recovery	(4,094)	(9,528)
Increase (decrease) in income tax recovery resulting from:
Derivative liability	843	1,171
Share based payments	467	453
Other permanent difference	(420)	(446)
Effect of change in statutory rate		5,938
State deferred change		(2,050)
Foreign income taxed at foreign rate	77	118
Increase in valuation allowance	$ 3,127	$ 4,344