v3.19.3
Document and Entity Information - shares
9 Months Ended
Sep. 30, 2019
Nov. 04, 2019
Cover [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Sep. 30, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q3  
Trading Symbol MTEM  
Entity Registrant Name Molecular Templates, Inc.  
Entity Central Index Key 0001183765  
Current Fiscal Year End Date --12-31  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity File Number 001-32979  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 94-3409596  
Entity Address, Address Line One 9301 Amberglen Blvd  
Entity Address, Address Line Two Suite 100  
Entity Address, City or Town Austin  
Entity Address, State or Province TX  
Entity Address, Postal Zip Code 78729  
City Area Code 512  
Local Phone Number 869-1555  
Entity Common Stock, Shares Outstanding   36,968,510
Title of 12(b) Security Common Stock, $0.001 Par Value Per Share  
Security Exchange Name NASDAQ  
Document Quarterly Report true  
Document Transition Report false