v3.7.0.1
Document And Entity Information - shares
3 Months Ended
Mar. 31, 2017
May 05, 2017
Document And Entity Information [Abstract]    
Entity Registrant Name Xenon Pharmaceuticals Inc.  
Document Type 10-Q  
Trading Symbol XENE  
Current Fiscal Year End Date --12-31  
Entity Common Stock, Shares Outstanding   17,996,680
Amendment Flag false  
Entity Central Index Key 0001582313  
Entity Filer Category Accelerated Filer  
Document Period End Date Mar. 31, 2017  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q1