v3.19.1
Document and Entity Information - shares
3 Months Ended
Mar. 31, 2019
Apr. 30, 2019
Document and Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Mar. 31, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q1  
Entity Registrant Name Intersect ENT, Inc.  
Entity Central Index Key 0001271214  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Trading Symbol XENT  
Entity Common Stock, Shares Outstanding   31,246,267
Entity Emerging Growth Company false  
Entity Small Business false