Molecular Templates, Inc. Quarterly report pursuant to Section 13 or 15(d)

Marketable Securities and Fair Value Measurements - Financial Liabilities at Fair Value on Recurring Basis (Detail) - 2017 Warrants - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial liabilities	$ 7	$ 3
Basis of Fair Value Measurements, Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial liabilities	0	0
Basis of Fair Value Measurements, Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial liabilities	0	0
Basis of Fair Value Measurements, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total financial liabilities	$ 7	$ 3