XML 12 R1.htm IDEA: XBRL DOCUMENT v3.21.1
Document and Entity Information - shares
6 Months Ended
Mar. 31, 2021
Apr. 26, 2021
Cover [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Mar. 31, 2021  
Document Fiscal Year Focus 2021  
Document Fiscal Period Focus Q2  
Trading Symbol ENTA  
Entity Registrant Name ENANTA PHARMACEUTICALS, INC  
Entity Central Index Key 0001177648  
Current Fiscal Year End Date --09-30  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity File Number 001-35839  
Security Exchange Name NASDAQ  
Entity Tax Identification Number 04-3205099  
Entity Address, Address Line One 500 Arsenal Street  
Entity Address, City or Town Watertown  
Entity Address, State or Province MA  
Entity Address, Postal Zip Code 02472  
City Area Code 617  
Title of 12(b) Security Common Stock, par value $0.01 per share  
Local Phone Number 607-0800  
Entity Incorporation, State or Country Code DE  
Document Transition Report false  
Document Quarterly Report true  
Entity Interactive Data Current Yes  
Entity Current Reporting Status Yes  
Entity Common Stock, Shares Outstanding   20,195,129