Molecular Templates, Inc. Annual report pursuant to Section 13 and 15(d)

Annual report pursuant to Section 13 and 15(d)

Equity Incentive Plans and Stock Based Compensation - Additional Information (Detail)

Equity Incentive Plans and Stock Based Compensation - Additional Information (Detail) - USD ($)			1 Months Ended		12 Months Ended
	Aug. 01, 2017	Jan. 01, 2017	May 31, 2018	Aug. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Apr. 30, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total intrinsic value of stock options exercised					$ 2,600,000	$ 78,000
Cash received from stock option exercises					283,000	61,000
Tax benefit realized upon exercise of option					0
Stock-based compensation expense					3,992,000	1,792,000
Unrecognized compensation cost related to unvested stock-based awards granted to employees under the stock option plans					$ 13,000,000
Unrecognized compensation cost related to unvested stock-based awards granted to employees under the stock option plans, period for recognition					2 years 10 months 24 days
2014 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price as a percentage of fair market value of common stock				100.00%
Terms of stock options granted					10 years
Terms of stock options vested					4 years
Options reserved for issuance transferred to 2018 Equity Incentive Plan							322,290
Stock-based compensation expense related to acceleration of vesting of pre-merger awards	$ 1,200,000					$ 1,200,000
2009 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Terms of stock options vested					5 years
Percentage of shares vesting on one-year anniversary and equal monthly vesting installments thereafter					20.00%
Options reserved for issuance transferred to 2018 Equity Incentive Plan							104,184
2004 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price as a percentage of fair market value of common stock					100.00%
Terms of stock options granted					10 years
Terms of stock options vested					4 years
2018 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price as a percentage of fair market value of common stock			100.00%
Terms of stock options granted					10 years
Terms of stock options vested					4 years
Options to purchase shares of common stock available for future grants					595,710
Options reserved for issuance transferred to 2018 Equity Incentive Plan							2,000,000
Common stock additional shares may be added to plan in connection in forfeiture or expiration of awards outstanding			2,885,121
2018 Equity incentive plan annual evergreen provision to increase available for issuance description					Additionally, the number of shares of common stock that may be issued under the 2018 Plan will automatically increase on each January 1, beginning with January 1, 2019, and continuing with January 1, 2028 by an amount equal to the lesser of (i) 4% of the number of outstanding shares of common stock on that date and (ii) an amount determined by the Company’s board of directors or compensation committee; provided, however, that in no event will the number of shares available for issuance under the 2018 Plan be increased to the extent such increase, in addition to any other increases proposed by the board of directors in the number of shares available for issuance under all other employee or director stock plan would result in the total number of shares then available for issuance under all employee and director stock plans exceeding 20% of the outstanding shares of the Company’s common stock on the first day of the applicable fiscal year.
Annual evergreen provision to increase available for issuance not to exceed percentage of common stock shares outstanding on date of increase			4.00%
2018 Equity Incentive Plan \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Available for issuance for all plans not to exceed percentage of common stock outstanding on first day of fiscal year			20.00%
2004 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options to purchase shares of common stock available for future grants					18,917
Additional shares authorized for issuance		9,091
Offering period					24 months
Purchase period					6 months
Discount available to eligible employees related to employee stock purchase plan					85.00%
Plan participants purchased shares					0	2,868
Average purchase price under 2004 Employee Stock Purchase Plan						$ 2.80