v3.8.0.1
Credit Facility - Additional Information (Details) - Line of Credit - Revolving Line of Credit - Silicon Valley Bank - CAD
3 Months Ended
Mar. 31, 2017
Dec. 31, 2017
Mar. 31, 2015
Line of Credit Facility [Line Items]      
Line of credit facility, maximum borrowing capacity     CAD 8,000
Effective interest rate (as a percent)   3.50%  
Line of credit facility, amount drawn   CAD 0  
U.S. Prime Rate      
Line of Credit Facility [Line Items]      
Interest rate basis spread 0.30%