XML 37 R44.htm IDEA: XBRL DOCUMENT v2.4.1.9
Fair Value Measurement (Details) (Recurring, USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value $ 7,455us-gaap_AssetsFairValueDisclosure $ 16,086us-gaap_AssetsFairValueDisclosure
Liabilities, fair value 16,244us-gaap_LiabilitiesFairValueDisclosure 25,904us-gaap_LiabilitiesFairValueDisclosure
Current portion of contingent liabilities - CyDex
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 6,796us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_CurrentPortionOfLiabilityForContingentValueRightsCompanyMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1] 1,712us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_CurrentPortionOfLiabilityForContingentValueRightsCompanyMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1]
Current portion of co-promote termination liability
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 322us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_CurrentPortionOfCoPromoteTerminationLiabilityMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2] 4,329us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_CurrentPortionOfCoPromoteTerminationLiabilityMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2]
Long-term portion of contingent liabilities - Metabasis
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 3,652us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LongTermPortionofLiabilityForContingentValueRightsCompanyMetabasisMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [3] 4,196us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LongTermPortionofLiabilityForContingentValueRightsCompanyMetabasisMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [3]
Long-term portion of contingent liabilities - CyDex
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 4,701us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForContingentValueRightCompanyOneMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1] 7,599us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForContingentValueRightCompanyOneMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1]
Liability for restricted investments owed to former licensees
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 773us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForRestrictedInvestmentsOwedToFormerLicenseesMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [4] 651us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForRestrictedInvestmentsOwedToFormerLicenseesMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [4]
Long-term portion of co-promote termination liability
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value   7,417us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LongTermPortionOfCoPromoteTerminationLiabilityMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2]
Current portion of co-promote termination payments receivable
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value 322us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= lgnd_CurrentPortionOfCoPromoteTerminationPaymentsReceivableMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2] 4,329us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= lgnd_CurrentPortionOfCoPromoteTerminationPaymentsReceivableMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2]
Short-term investments
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value 7,133us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_ShortTermInvestmentsMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [5]  
Available-for-sale securities
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value   4,340us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_AvailableforsaleSecuritiesMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [5]
Long-term portion of co-promote termination payments receivable
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value   7,417us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= lgnd_LongTermPortionOfCoPromoteTerminationPaymentsReceivableMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2]
Quoted Prices in Active Markets for Identical Assets (Level 1)
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value 7,133us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 4,340us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Liabilities, fair value 4,425us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 4,847us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Quoted Prices in Active Markets for Identical Assets (Level 1) | Current portion of contingent liabilities - CyDex
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_CurrentPortionOfLiabilityForContingentValueRightsCompanyMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1] 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_CurrentPortionOfLiabilityForContingentValueRightsCompanyMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1]
Quoted Prices in Active Markets for Identical Assets (Level 1) | Current portion of co-promote termination liability
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_CurrentPortionOfCoPromoteTerminationLiabilityMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2] 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_CurrentPortionOfCoPromoteTerminationLiabilityMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2]
Quoted Prices in Active Markets for Identical Assets (Level 1) | Long-term portion of contingent liabilities - Metabasis
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 3,652us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LongTermPortionofLiabilityForContingentValueRightsCompanyMetabasisMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [3] 4,196us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LongTermPortionofLiabilityForContingentValueRightsCompanyMetabasisMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [3]
Quoted Prices in Active Markets for Identical Assets (Level 1) | Long-term portion of contingent liabilities - CyDex
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForContingentValueRightCompanyOneMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1] 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForContingentValueRightCompanyOneMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1]
Quoted Prices in Active Markets for Identical Assets (Level 1) | Liability for restricted investments owed to former licensees
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 773us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForRestrictedInvestmentsOwedToFormerLicenseesMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [4] 651us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForRestrictedInvestmentsOwedToFormerLicenseesMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [4]
Quoted Prices in Active Markets for Identical Assets (Level 1) | Long-term portion of co-promote termination liability
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value   0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LongTermPortionOfCoPromoteTerminationLiabilityMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2]
Quoted Prices in Active Markets for Identical Assets (Level 1) | Current portion of co-promote termination payments receivable
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value 0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= lgnd_CurrentPortionOfCoPromoteTerminationPaymentsReceivableMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2] 0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= lgnd_CurrentPortionOfCoPromoteTerminationPaymentsReceivableMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2]
Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term investments
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value 7,133us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_ShortTermInvestmentsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [5]  
Quoted Prices in Active Markets for Identical Assets (Level 1) | Available-for-sale securities
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value   4,340us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_AvailableforsaleSecuritiesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [5]
Quoted Prices in Active Markets for Identical Assets (Level 1) | Long-term portion of co-promote termination payments receivable
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value   0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= lgnd_LongTermPortionOfCoPromoteTerminationPaymentsReceivableMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2]
Significant Other Observable Inputs (Level 2)
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value 0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Significant Other Observable Inputs (Level 2) | Current portion of contingent liabilities - CyDex
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_CurrentPortionOfLiabilityForContingentValueRightsCompanyMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1] 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_CurrentPortionOfLiabilityForContingentValueRightsCompanyMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1]
Significant Other Observable Inputs (Level 2) | Current portion of co-promote termination liability
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_CurrentPortionOfCoPromoteTerminationLiabilityMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2] 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_CurrentPortionOfCoPromoteTerminationLiabilityMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2]
Significant Other Observable Inputs (Level 2) | Long-term portion of contingent liabilities - Metabasis
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LongTermPortionofLiabilityForContingentValueRightsCompanyMetabasisMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [3] 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LongTermPortionofLiabilityForContingentValueRightsCompanyMetabasisMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [3]
Significant Other Observable Inputs (Level 2) | Long-term portion of contingent liabilities - CyDex
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForContingentValueRightCompanyOneMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1] 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForContingentValueRightCompanyOneMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1]
Significant Other Observable Inputs (Level 2) | Liability for restricted investments owed to former licensees
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForRestrictedInvestmentsOwedToFormerLicenseesMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [4] 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForRestrictedInvestmentsOwedToFormerLicenseesMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [4]
Significant Other Observable Inputs (Level 2) | Long-term portion of co-promote termination liability
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value   0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LongTermPortionOfCoPromoteTerminationLiabilityMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2]
Significant Other Observable Inputs (Level 2) | Current portion of co-promote termination payments receivable
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value 0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= lgnd_CurrentPortionOfCoPromoteTerminationPaymentsReceivableMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2] 0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= lgnd_CurrentPortionOfCoPromoteTerminationPaymentsReceivableMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2]
Significant Other Observable Inputs (Level 2) | Short-term investments
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value 0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_ShortTermInvestmentsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [5]  
Significant Other Observable Inputs (Level 2) | Available-for-sale securities
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value   0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_AvailableforsaleSecuritiesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [5]
Significant Other Observable Inputs (Level 2) | Long-term portion of co-promote termination payments receivable
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value   0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= lgnd_LongTermPortionOfCoPromoteTerminationPaymentsReceivableMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2]
Significant Unobservable Inputs (Level 3)
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value 322us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 11,746us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Liabilities, fair value 11,819us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 21,057us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
Significant Unobservable Inputs (Level 3) | Current portion of contingent liabilities - CyDex
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 6,796us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_CurrentPortionOfLiabilityForContingentValueRightsCompanyMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1] 1,712us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_CurrentPortionOfLiabilityForContingentValueRightsCompanyMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1]
Significant Unobservable Inputs (Level 3) | Current portion of co-promote termination liability
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 322us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_CurrentPortionOfCoPromoteTerminationLiabilityMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2] 4,329us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_CurrentPortionOfCoPromoteTerminationLiabilityMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2]
Significant Unobservable Inputs (Level 3) | Long-term portion of contingent liabilities - Metabasis
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LongTermPortionofLiabilityForContingentValueRightsCompanyMetabasisMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [3] 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LongTermPortionofLiabilityForContingentValueRightsCompanyMetabasisMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [3]
Significant Unobservable Inputs (Level 3) | Long-term portion of contingent liabilities - CyDex
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 4,701us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForContingentValueRightCompanyOneMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1] 7,599us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForContingentValueRightCompanyOneMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [1]
Significant Unobservable Inputs (Level 3) | Liability for restricted investments owed to former licensees
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForRestrictedInvestmentsOwedToFormerLicenseesMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [4] 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForRestrictedInvestmentsOwedToFormerLicenseesMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [4]
Significant Unobservable Inputs (Level 3) | Long-term portion of co-promote termination liability
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities, fair value   7,417us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LongTermPortionOfCoPromoteTerminationLiabilityMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2]
Significant Unobservable Inputs (Level 3) | Current portion of co-promote termination payments receivable
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value 322us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= lgnd_CurrentPortionOfCoPromoteTerminationPaymentsReceivableMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2] 4,329us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= lgnd_CurrentPortionOfCoPromoteTerminationPaymentsReceivableMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2]
Significant Unobservable Inputs (Level 3) | Short-term investments
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value 0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_ShortTermInvestmentsMember
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= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [5]  
Significant Unobservable Inputs (Level 3) | Available-for-sale securities
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value   0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
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= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [5]
Significant Unobservable Inputs (Level 3) | Long-term portion of co-promote termination payments receivable
    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets, fair value   $ 7,417us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= lgnd_LongTermPortionOfCoPromoteTerminationPaymentsReceivableMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember		 [2]
[1] The fair value of the liabilities for CyDex contingent liabilities were determined based on the income approach using a Monte Carlo analysis. The fair value is subjective and is affected by changes in inputs to the valuation model including management’s assumptions regarding revenue volatility, probability of commercialization of products, estimates of timing and probability of achievement of certain revenue thresholds and developmental and regulatory milestones which may be achieved and affect amounts owed to former license holders and CVR holders. Changes in these assumptions can materially affect the fair value estimate.
[2] The co-promote termination payments receivable represents a non-interest-bearing receivable for future payments to be made by Pfizer related to product sales and is recorded at its fair value. The receivable and liability will remain equal, and are adjusted each quarter for changes in the fair value of the obligation including any changes in the estimate of future net Avinza product sales. The fair value is determined based on a valuation model using an income approach. For additional information, see Note 4 Avinza Co-Promotion.
[3] The liability for CVRs for Metabasis are determined using quoted market prices in active markets for the underlying CVR.
[4] The liability for amounts owed to former licensees are determined using quoted market prices in active markets for the underlying investment received from a partner, a portion of which is owed to former licensors.
[5] The Company’s short-term investments include investments in equity securities which the Company received as a result of event-based and upfront payments from licensees. The fair value is determined using quoted market prices in active markets for the same securities.