v3.19.1
Document And Entity Information - shares
3 Months Ended
Mar. 31, 2019
May 07, 2019
Document Information [Line Items]    
Entity Registrant Name Vaxart, Inc.  
Entity Central Index Key 0000072444  
Trading Symbol vxrt  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Entity Current Reporting Status Yes  
Entity Emerging Growth Company false  
Entity Small Business true  
Entity Common Stock, Shares Outstanding (in shares)   15,785,735
Document Type 10-Q  
Document Period End Date Mar. 31, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q1  
Amendment Flag false