Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Details)

v2.4.1.9
Fair Value Measurements (Details) (USD $)
Mar. 31, 2015
Dec. 31, 2014
Aug. 31, 2014
2019 convertible senior notes      
Liabilities:      
Principal amount outstanding $ 245,000,000us-gaap_DebtInstrumentFaceAmount
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= lgnd_A2019ConvertibleSeniorNotesMember
$ 245,000,000us-gaap_DebtInstrumentFaceAmount
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= lgnd_A2019ConvertibleSeniorNotesMember
 
Estimated fair value of debt 297,100,000us-gaap_ConvertibleDebtFairValueDisclosures
/ us-gaap_DebtInstrumentAxis
= lgnd_A2019ConvertibleSeniorNotesMember
   
2019 convertible senior notes | Senior Notes      
Liabilities:      
Principal amount outstanding     245,000,000us-gaap_DebtInstrumentFaceAmount
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= lgnd_A2019ConvertibleSeniorNotesMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Recurring      
Assets:      
Assets, fair value 11,547,000us-gaap_AssetsFairValueDisclosure
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= us-gaap_FairValueMeasurementsRecurringMember
7,455,000us-gaap_AssetsFairValueDisclosure
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= us-gaap_FairValueMeasurementsRecurringMember
 
Liabilities:      
Liabilities, fair value 13,422,000us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
16,244,000us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
 
Recurring | Current contingent liabilities-CyDex      
Liabilities:      
Liabilities, fair value 3,692,000us-gaap_LiabilitiesFairValueDisclosure
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= lgnd_CurrentPortionOfLiabilityForContingentValueRightsCompanyMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
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6,796,000us-gaap_LiabilitiesFairValueDisclosure
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= lgnd_CurrentPortionOfLiabilityForContingentValueRightsCompanyMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
 
Recurring | Current co-promote termination liability      
Liabilities:      
Liabilities, fair value 88,000us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_CurrentPortionOfCoPromoteTerminationLiabilityMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
322,000us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_CurrentPortionOfCoPromoteTerminationLiabilityMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
 
Recurring | Long-term contingent liabilities-Metabasis      
Liabilities:      
Liabilities, fair value 2,495,000us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LongTermPortionofLiabilityForContingentValueRightsCompanyMetabasisMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
3,652,000us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LongTermPortionofLiabilityForContingentValueRightsCompanyMetabasisMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
 
Recurring | Long-term contingent liabilities-CyDex      
Liabilities:      
Liabilities, fair value 5,718,000us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LongTermPortionOfLiabilityForContingentValueRightsCompanyMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
4,701,000us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LongTermPortionOfLiabilityForContingentValueRightsCompanyMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
 
Recurring | Liability for amounts owed to former licensees      
Liabilities:      
Liabilities, fair value 1,429,000us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForRestrictedInvestmentsOwedToFormerLicenseesMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
773,000us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForRestrictedInvestmentsOwedToFormerLicenseesMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
 
Recurring | Current co-promote termination payments receivable      
Assets:      
Assets, fair value 88,000us-gaap_AssetsFairValueDisclosure
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= lgnd_CurrentPortionOfCoPromoteTerminationPaymentsReceivableMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
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322,000us-gaap_AssetsFairValueDisclosure
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= lgnd_CurrentPortionOfCoPromoteTerminationPaymentsReceivableMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
 
Recurring | Short-term investments      
Assets:      
Assets, fair value 11,459,000us-gaap_AssetsFairValueDisclosure
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= us-gaap_AvailableforsaleSecuritiesMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
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7,133,000us-gaap_AssetsFairValueDisclosure
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= us-gaap_AvailableforsaleSecuritiesMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
 
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)      
Assets:      
Assets, fair value 11,459,000us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
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7,133,000us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
 
Liabilities:      
Liabilities, fair value 3,924,000us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
4,425,000us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
 
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Current contingent liabilities-CyDex      
Liabilities:      
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByLiabilityClassAxis
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0us-gaap_LiabilitiesFairValueDisclosure
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= us-gaap_FairValueMeasurementsRecurringMember
 
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Current co-promote termination liability      
Liabilities:      
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
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= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByLiabilityClassAxis
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0us-gaap_LiabilitiesFairValueDisclosure
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= us-gaap_FairValueMeasurementsRecurringMember
 
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Long-term contingent liabilities-Metabasis      
Liabilities:      
Liabilities, fair value 2,495,000us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByLiabilityClassAxis
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/ us-gaap_FairValueByMeasurementFrequencyAxis
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3,652,000us-gaap_LiabilitiesFairValueDisclosure
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= us-gaap_FairValueMeasurementsRecurringMember
 
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Long-term contingent liabilities-CyDex      
Liabilities:      
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByLiabilityClassAxis
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0us-gaap_LiabilitiesFairValueDisclosure
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= us-gaap_FairValueMeasurementsRecurringMember
 
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Liability for amounts owed to former licensees      
Liabilities:      
Liabilities, fair value 1,429,000us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForRestrictedInvestmentsOwedToFormerLicenseesMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
773,000us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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/ us-gaap_FairValueByLiabilityClassAxis
= lgnd_LiabilityForRestrictedInvestmentsOwedToFormerLicenseesMember
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
 
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Current co-promote termination payments receivable      
Assets:      
Assets, fair value 0us-gaap_AssetsFairValueDisclosure
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= lgnd_CurrentPortionOfCoPromoteTerminationPaymentsReceivableMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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0us-gaap_AssetsFairValueDisclosure
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= us-gaap_FairValueMeasurementsRecurringMember
 
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term investments      
Assets:      
Assets, fair value 11,459,000us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_AvailableforsaleSecuritiesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
7,133,000us-gaap_AssetsFairValueDisclosure
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= us-gaap_AvailableforsaleSecuritiesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
 
Recurring | Significant Other Observable Inputs (Level 2)      
Assets:      
Assets, fair value 0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
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0us-gaap_AssetsFairValueDisclosure
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= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
 
Liabilities:      
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
0us-gaap_LiabilitiesFairValueDisclosure
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= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
= us-gaap_FairValueMeasurementsRecurringMember
 
Recurring | Significant Other Observable Inputs (Level 2) | Current contingent liabilities-CyDex      
Liabilities:      
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByLiabilityClassAxis
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0us-gaap_LiabilitiesFairValueDisclosure
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= us-gaap_FairValueMeasurementsRecurringMember
 
Recurring | Significant Other Observable Inputs (Level 2) | Current co-promote termination liability      
Liabilities:      
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByLiabilityClassAxis
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Recurring | Significant Other Observable Inputs (Level 2) | Long-term contingent liabilities-Metabasis      
Liabilities:      
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
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Recurring | Significant Other Observable Inputs (Level 2) | Long-term contingent liabilities-CyDex      
Liabilities:      
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByLiabilityClassAxis
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Recurring | Significant Other Observable Inputs (Level 2) | Liability for amounts owed to former licensees      
Liabilities:      
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_FairValueByLiabilityClassAxis
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0us-gaap_LiabilitiesFairValueDisclosure
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Recurring | Significant Other Observable Inputs (Level 2) | Current co-promote termination payments receivable      
Assets:      
Assets, fair value 0us-gaap_AssetsFairValueDisclosure
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= lgnd_CurrentPortionOfCoPromoteTerminationPaymentsReceivableMember
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Recurring | Significant Other Observable Inputs (Level 2) | Short-term investments      
Assets:      
Assets, fair value 0us-gaap_AssetsFairValueDisclosure
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Recurring | Significant Unobservable Inputs (Level 3)      
Assets:      
Assets, fair value 88,000us-gaap_AssetsFairValueDisclosure
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= us-gaap_FairValueInputsLevel3Member
/ us-gaap_FairValueByMeasurementFrequencyAxis
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322,000us-gaap_AssetsFairValueDisclosure
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Liabilities:      
Liabilities, fair value 9,498,000us-gaap_LiabilitiesFairValueDisclosure
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11,819,000us-gaap_LiabilitiesFairValueDisclosure
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Recurring | Significant Unobservable Inputs (Level 3) | Current contingent liabilities-CyDex      
Liabilities:      
Liabilities, fair value 3,692,000us-gaap_LiabilitiesFairValueDisclosure
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6,796,000us-gaap_LiabilitiesFairValueDisclosure
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Recurring | Significant Unobservable Inputs (Level 3) | Current co-promote termination liability      
Liabilities:      
Liabilities, fair value 88,000us-gaap_LiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
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322,000us-gaap_LiabilitiesFairValueDisclosure
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Recurring | Significant Unobservable Inputs (Level 3) | Long-term contingent liabilities-Metabasis      
Liabilities:      
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
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Recurring | Significant Unobservable Inputs (Level 3) | Long-term contingent liabilities-CyDex      
Liabilities:      
Liabilities, fair value 5,718,000us-gaap_LiabilitiesFairValueDisclosure
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= us-gaap_FairValueInputsLevel3Member
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4,701,000us-gaap_LiabilitiesFairValueDisclosure
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Recurring | Significant Unobservable Inputs (Level 3) | Liability for amounts owed to former licensees      
Liabilities:      
Liabilities, fair value 0us-gaap_LiabilitiesFairValueDisclosure
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0us-gaap_LiabilitiesFairValueDisclosure
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Recurring | Significant Unobservable Inputs (Level 3) | Current co-promote termination payments receivable      
Assets:      
Assets, fair value 88,000us-gaap_AssetsFairValueDisclosure
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322,000us-gaap_AssetsFairValueDisclosure
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Recurring | Significant Unobservable Inputs (Level 3) | Short-term investments      
Assets:      
Assets, fair value $ 0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
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$ 0us-gaap_AssetsFairValueDisclosure
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