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

Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements and Marketable Securities - Summary of Company's Available-for-Sale Securities (Detail)

Fair Value Measurements and Marketable Securities - Summary of Company's Available-for-Sale Securities (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	$ 79,630	$ 74,726
Unrealized Gain	31	38
Unrealized Loss	(18)	(10)
Fair Value	79,643	74,754
Money Market Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	5,001	4,285
Unrealized Gain
Unrealized Loss
Fair Value	5,001	4,285
Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	1,464	1,584
Unrealized Gain
Unrealized Loss
Fair Value	1,464	1,584
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	55,318	49,001
Unrealized Gain	15	25
Unrealized Loss	(16)	(7)
Fair Value	55,317	49,019
U. S. Government Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	18,977	21,722
Unrealized Gain	15	12
Unrealized Loss	(2)	(3)
Fair Value	18,990	21,731
Municipal Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	1,617	2,814
Unrealized Gain	1	1
Unrealized Loss
Fair Value	1,618	2,815
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	3,996	2,599
Unrealized Gain
Unrealized Loss
Fair Value	3,996	2,599
Marketable Securities Including Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	86,373	82,005
Unrealized Gain	31	38
Unrealized Loss	(18)	(10)
Fair Value	86,386	82,033
Less Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	6,743	7,279
Unrealized Gain
Unrealized Loss
Fair Value	$ 6,743	$ 7,279