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Stock Based Compensation - Additional Information (Detail) (USD $)
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3 Months Ended | 0 Months Ended | |
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Mar. 31, 2015
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Mar. 31, 2014
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Jan. 01, 2015
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| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
| Stock-based compensation expense | $ 1,421,000us-gaap_AllocatedShareBasedCompensationExpense | $ 1,266,000us-gaap_AllocatedShareBasedCompensationExpense | |
| Unrecognized compensation cost related to unvested stock-based awards granted to employees under the stock option plans | 14,600,000us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized | ||
| Unrecognized compensation cost related to unvested stock-based awards granted to employees under the stock option plans, period for recognition | 2 years 10 months 13 days | 2 years 10 months 13 days | |
| Non-employee stock-based compensation expense | 24,000us-gaap_IssuanceOfStockAndWarrantsForServicesOrClaims | 36,000us-gaap_IssuanceOfStockAndWarrantsForServicesOrClaims | |
| Total intrinsic value of stock options exercised | 200,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue | 100,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue | |
| Cash received from stock option exercises | 100,000us-gaap_ProceedsFromStockOptionsExercised | 100,000us-gaap_ProceedsFromStockOptionsExercised | |
| Tax benefit realized upon exercise of option | 0us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitRealizedFromExerciseOfStockOptions | 0us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitRealizedFromExerciseOfStockOptions | |
| 2014 Equity Incentive Plan | |||
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
| Remaining shares available for issuance |
2,537,763us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant / us-gaap_PlanNameAxis = thld_TwoThousandAndFourteenEquityIncentivePlanMember |
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| 2004 Employee Stock Purchase Plan | |||
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | |||
| Remaining shares available for issuance |
206,231us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant / us-gaap_PlanNameAxis = thld_TwoThousandFourEmployeeStockPurchasePlanMember |
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| Additional shares authorized for issuance |
100,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized / us-gaap_PlanNameAxis = thld_TwoThousandFourEmployeeStockPurchasePlanMember |
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| Plan participants purchased shares |
74,673us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesPurchasedForAward / us-gaap_PlanNameAxis = thld_TwoThousandFourEmployeeStockPurchasePlanMember |
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| Average purchase price under 2004 Employee Stock Purchase Plan |
$ 3.43us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerShareWeightedAveragePriceOfSharesPurchased / us-gaap_PlanNameAxis = thld_TwoThousandFourEmployeeStockPurchasePlanMember |
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| Cash proceeds |
$ 300,000us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlans / us-gaap_PlanNameAxis = thld_TwoThousandFourEmployeeStockPurchasePlanMember |
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- Definition
Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Unrecognized cost of unvested share-based compensation awards. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Disclosure of the aggregate tax benefit realized from the exercise of stock options and the conversion of similar instruments during the annual period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Fair value of share-based compensation granted to nonemployees as payment for services rendered or acknowledged claims. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The cash inflow associated with the amount received from holders to acquire the entity's shares under incentive and share awards other than stock option exercises. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately. No definition available.
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- Definition
The cash inflow associated with the amount received from holders exercising their stock options. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
Number of additional shares authorized for issuance under an established share-based compensation plan. No definition available.
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- Definition
The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The weighted average of per share prices paid for shares purchased on the open market for issuance to employees under the plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The number of shares purchased on the open market during the period for issuance to employees under the plan. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Details
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