Molecular Templates, Inc. Annual report pursuant to Section 13 and 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	Dec. 31, 2014	Dec. 31, 2013
Schedule Of Available For Sale Securities [Line Items]
Cost Basis	$ 50,222	$ 74,726
Unrealized Gain	4	38
Unrealized Loss	(17)	(10)
Fair Value	50,209us-gaap_AvailableForSaleSecurities	74,754us-gaap_AvailableForSaleSecurities
Money Market Funds
Schedule Of Available For Sale Securities [Line Items]
Cost Basis	3,369	4,285
Unrealized Gain	0	0
Unrealized Loss	0	0
Fair Value	3,369	4,285
Certificates of Deposit
Schedule Of Available For Sale Securities [Line Items]
Cost Basis	2,505	1,584
Unrealized Gain	0	0
Unrealized Loss	0	0
Fair Value	2,505	1,584
Corporate Debt Securities
Schedule Of Available For Sale Securities [Line Items]
Cost Basis	28,094	49,001
Unrealized Gain	1	25
Unrealized Loss	(14)	(7)
Fair Value	28,081	49,019
Government Securities
Schedule Of Available For Sale Securities [Line Items]
Cost Basis	19,123	21,722
Unrealized Gain	3	12
Unrealized Loss	(3)	(3)
Fair Value	19,123	21,731
Municipal Securities
Schedule Of Available For Sale Securities [Line Items]
Cost Basis		2,814
Unrealized Gain		1
Unrealized Loss		0
Fair Value		2,815
Commercial Paper
Schedule Of Available For Sale Securities [Line Items]
Cost Basis	5,499	2,599
Unrealized Gain	0	0
Unrealized Loss	0	0
Fair Value	5,499	2,599
Marketable Securities Including Cash Equivalents
Schedule Of Available For Sale Securities [Line Items]
Cost Basis	58,590	82,005
Unrealized Gain	4	38
Unrealized Loss	(17)	(10)
Fair Value	58,577	82,033
Less Cash Equivalents
Schedule Of Available For Sale Securities [Line Items]
Cost Basis	(8,368)	7,279
Unrealized Gain	0	0
Unrealized Loss	0	0
Fair Value	$ (8,368)	$ 7,279