Fair Value Measurements and Marketable Securities - Summary of Company's Available-for-Sale Securities (Detail) (USD $)
In Thousands, unless otherwise specified |
Mar. 31, 2015
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Dec. 31, 2014
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Schedule Of Available For Sale Securities [Line Items] | ||
Cost Basis | $ 62,038us-gaap_AvailableForSaleSecuritiesAmortizedCost | $ 50,222us-gaap_AvailableForSaleSecuritiesAmortizedCost |
Unrealized Gain | 6us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax | 4us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax |
Unrealized Loss | (21)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax | (17)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax |
Fair Value | 62,023us-gaap_AvailableForSaleSecurities | 50,209us-gaap_AvailableForSaleSecurities |
Money Market Funds | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Cost Basis |
10,366us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember |
3,369us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember |
Unrealized Gain |
0us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember |
0us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember |
Unrealized Loss |
0us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember |
0us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember |
Fair Value |
10,366us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember |
3,369us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember |
Certificates of Deposit | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Cost Basis |
1,475us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_CertificatesOfDepositMember |
2,505us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_CertificatesOfDepositMember |
Unrealized Gain |
0us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_CertificatesOfDepositMember |
0us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_CertificatesOfDepositMember |
Unrealized Loss |
0us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_CertificatesOfDepositMember |
0us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_CertificatesOfDepositMember |
Fair Value |
1,475us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CertificatesOfDepositMember |
2,505us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CertificatesOfDepositMember |
Corporate Debt Securities | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Cost Basis |
31,950us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember |
28,094us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember |
Unrealized Gain |
4us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember |
1us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember |
Unrealized Loss |
(19)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember |
(14)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember |
Fair Value |
31,935us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember |
28,081us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CorporateDebtSecuritiesMember |
U.S. Government Securities | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Cost Basis |
24,021us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember |
19,123us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember |
Unrealized Gain |
2us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember |
3us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember |
Unrealized Loss |
(2)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember |
(3)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember |
Fair Value |
24,021us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember |
19,123us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_USGovernmentDebtSecuritiesMember |
Commercial Paper | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Cost Basis |
14,240us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_CommercialPaperMember |
5,499us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_CommercialPaperMember |
Unrealized Gain |
0us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_CommercialPaperMember |
0us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_CommercialPaperMember |
Unrealized Loss |
0us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_CommercialPaperMember |
0us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_CommercialPaperMember |
Fair Value |
14,240us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CommercialPaperMember |
5,499us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CommercialPaperMember |
Marketable Securities Including Cash Equivalents | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Cost Basis |
82,052us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = thld_MarketableSecuritiesIncludingCashEquivalentsMember |
58,590us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = thld_MarketableSecuritiesIncludingCashEquivalentsMember |
Unrealized Gain |
6us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_FairValueByAssetClassAxis = thld_MarketableSecuritiesIncludingCashEquivalentsMember |
4us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_FairValueByAssetClassAxis = thld_MarketableSecuritiesIncludingCashEquivalentsMember |
Unrealized Loss |
(21)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_FairValueByAssetClassAxis = thld_MarketableSecuritiesIncludingCashEquivalentsMember |
(17)us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_FairValueByAssetClassAxis = thld_MarketableSecuritiesIncludingCashEquivalentsMember |
Fair Value |
82,037us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = thld_MarketableSecuritiesIncludingCashEquivalentsMember |
58,577us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = thld_MarketableSecuritiesIncludingCashEquivalentsMember |
Less Cash Equivalents | ||
Schedule Of Available For Sale Securities [Line Items] | ||
Cost Basis |
20,014us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_CashEquivalentsMember |
8,368us-gaap_AvailableForSaleSecuritiesAmortizedCost / us-gaap_FairValueByAssetClassAxis = us-gaap_CashEquivalentsMember |
Unrealized Gain |
0us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_CashEquivalentsMember |
0us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_CashEquivalentsMember |
Unrealized Loss |
0us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_CashEquivalentsMember |
0us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax / us-gaap_FairValueByAssetClassAxis = us-gaap_CashEquivalentsMember |
Fair Value |
$ 20,014us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CashEquivalentsMember |
$ 8,368us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByAssetClassAxis = us-gaap_CashEquivalentsMember |
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- Definition
Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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