Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plan - Additional Information (Detail)

v3.20.1
Employee Benefit Plan - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Molecular Templates 401(k) Plan    
Defined Contribution Plan Disclosure [Line Items]    
Employer discretionary contribution amount $ 0.2 $ 0.1