Quarterly report pursuant to Section 13 or 15(d)

Variable Interest Entities (Details)

v2.4.1.9
Variable Interest Entities (Details) (USD $)
3 Months Ended 1 Months Ended 7 Months Ended 12 Months Ended 3 Months Ended 0 Months Ended 1 Months Ended 0 Months Ended
Mar. 31, 2015
May 31, 2014
program
Apr. 30, 2015
Dec. 31, 2014
Mar. 31, 2014
Jan. 01, 2016
May 11, 2015
Apr. 30, 2015
May 04, 2015
Dec. 31, 2013
Variable Interest Entity [Line Items]                    
Loss percentage recorded 100.00%lgnd_VariableInterestEntityQualitativeorQuantitativeInformationLossPercentageRecorded                  
Cash and cash equivalents $ 165,766,000us-gaap_CashAndCashEquivalentsAtCarryingValue     160,203,000us-gaap_CashAndCashEquivalentsAtCarryingValue $ 12,977,000us-gaap_CashAndCashEquivalentsAtCarryingValue         $ 11,639,000us-gaap_CashAndCashEquivalentsAtCarryingValue
Other current assets 926,000us-gaap_OtherAssetsCurrent     1,520,000us-gaap_OtherAssetsCurrent            
Capitalized IPO expenses, VIE 2,408,000lgnd_CapitalizedInitialPublicOfferingExpenses     2,268,000lgnd_CapitalizedInitialPublicOfferingExpenses            
Total current assets 191,713,000us-gaap_AssetsCurrent     185,158,000us-gaap_AssetsCurrent            
Other assets 358,000us-gaap_OtherAssetsNoncurrent     207,000us-gaap_OtherAssetsNoncurrent            
Total assets 263,223,000us-gaap_Assets     258,029,000us-gaap_Assets            
Accounts payable 7,442,000us-gaap_AccountsPayableCurrent     7,698,000us-gaap_AccountsPayableCurrent            
Accrued liabilities 4,263,000us-gaap_AccruedLiabilitiesCurrent     4,866,000us-gaap_AccruedLiabilitiesCurrent            
Current note payable, VIE 348,000us-gaap_NotesPayableCurrent     334,000us-gaap_NotesPayableCurrent            
Total current liabilities 18,157,000us-gaap_LiabilitiesCurrent     22,779,000us-gaap_LiabilitiesCurrent            
Total liabilities 230,828,000us-gaap_Liabilities     233,621,000us-gaap_Liabilities            
Viking                    
Variable Interest Entity [Line Items]                    
Number of programs licensed   5lgnd_VariableInterestEntityNumberofProgramsLicensed
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
               
Convertible loan facility 2,000,000us-gaap_VariableInterestEntityFinancialOrOtherSupportAmount
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
                 
Cash and cash equivalents 327,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
    756,000us-gaap_CashAndCashEquivalentsAtCarryingValue
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
           
Other current assets 32,000us-gaap_OtherAssetsCurrent
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
    18,000us-gaap_OtherAssetsCurrent
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
           
Capitalized IPO expenses, VIE 2,408,000lgnd_CapitalizedInitialPublicOfferingExpenses
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
    2,268,000lgnd_CapitalizedInitialPublicOfferingExpenses
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
           
Total current assets 2,767,000us-gaap_AssetsCurrent
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
    3,042,000us-gaap_AssetsCurrent
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
           
Other assets 1,000us-gaap_OtherAssetsNoncurrent
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
    1,000us-gaap_OtherAssetsNoncurrent
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
           
Total assets 2,768,000us-gaap_Assets
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
    3,043,000us-gaap_Assets
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
           
Accounts payable 2,397,000us-gaap_AccountsPayableCurrent
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
    2,211,000us-gaap_AccountsPayableCurrent
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
           
Accrued liabilities 113,000us-gaap_AccruedLiabilitiesCurrent
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
    77,000us-gaap_AccruedLiabilitiesCurrent
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
           
Current note payable, VIE 348,000us-gaap_NotesPayableCurrent
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
    334,000us-gaap_NotesPayableCurrent
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
           
Total current liabilities 2,858,000us-gaap_LiabilitiesCurrent
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
    2,622,000us-gaap_LiabilitiesCurrent
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
           
Long-term portion of notes payable 2,663,000us-gaap_LongTermNotesPayable
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
    2,331,000us-gaap_LongTermNotesPayable
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
           
Total liabilities 5,521,000us-gaap_Liabilities
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
    4,953,000us-gaap_Liabilities
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
           
Viking | Forecast                    
Variable Interest Entity [Line Items]                    
Value of common stock issued upon IPO     29,000,000lgnd_VariableInterestEntityCommonStockIssuedUponIPOValue
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioForecastMember
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
             
Threshold proceeds from private financing     20,000,000us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityOtherMeasureOfActivityAmount
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioForecastMember
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
             
Contingencies for repayment of debt     20,000,000lgnd_RepaymentofDebtMinimumNetProceedsfromIPOorOtherFinancingforRepaymentofDebttoOccurwithinOneYear
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioForecastMember
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
             
Period after close of IPO when debt becomes due     1 year              
Debt | Viking                    
Variable Interest Entity [Line Items]                    
Convertible loan facility   2,500,000us-gaap_VariableInterestEntityFinancialOrOtherSupportAmount
/ us-gaap_DerivativeByNatureAxis
= us-gaap_DebtMember
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
               
Interest accrual rate, less than   5.00%lgnd_VariableInterestEntityInterestAccrualRatePercentLessThanMaximum
/ us-gaap_DerivativeByNatureAxis
= us-gaap_DebtMember
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
               
Repayment in equity percentage       200.00%lgnd_VariableInterestEntityLicenseAgreementRepaymentinEquityRepaymentPercentage
/ us-gaap_DerivativeByNatureAxis
= us-gaap_DebtMember
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
           
Metabasis Therapeutics                    
Variable Interest Entity [Line Items]                    
Contingent liability change in amount 1,200,000us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1
/ us-gaap_BusinessAcquisitionAxis
= lgnd_MetabasisTherapeuticsMember
      (2,500,000)us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1
/ us-gaap_BusinessAcquisitionAxis
= lgnd_MetabasisTherapeuticsMember
         
Metabasis Therapeutics | Forecast                    
Variable Interest Entity [Line Items]                    
Contingent liability change in amount           3,200,000us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1
/ us-gaap_BusinessAcquisitionAxis
= lgnd_MetabasisTherapeuticsMember
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioForecastMember
       
Subsequent Event | Viking                    
Variable Interest Entity [Line Items]                    
Ownership after close of IPO (percent)             49.80%us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
     
Subsequent Event | IPO | Viking                    
Variable Interest Entity [Line Items]                    
Ownership after close of IPO (percent)               49.90%us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
/ us-gaap_SubsidiarySaleOfStockAxis
= us-gaap_IPOMember
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
   
Shares issued in IPO (shares)             3,000,000us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
/ us-gaap_SubsidiarySaleOfStockAxis
= us-gaap_IPOMember
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
     
IPO share price (USD per share)             8.00us-gaap_SaleOfStockPricePerShare
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
/ us-gaap_SubsidiarySaleOfStockAxis
= us-gaap_IPOMember
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
     
IPO shares purchased by the Company (shares)             1,100,000lgnd_EquityMethodInvestmentsSharesPurchased
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
/ us-gaap_SubsidiarySaleOfStockAxis
= us-gaap_IPOMember
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
     
Payments to acquire IPO shares             9,000,000us-gaap_PaymentsToAcquireEquityMethodInvestments
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
/ us-gaap_SubsidiarySaleOfStockAxis
= us-gaap_IPOMember
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
     
IPO shares received pursuant to amended MLA (shares)             3,400,000lgnd_EquityInvestmentSharesReceivedLicensingAgreement
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
/ us-gaap_SubsidiarySaleOfStockAxis
= us-gaap_IPOMember
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
     
Subsequent Event | Over-Allotment Option | Viking                    
Variable Interest Entity [Line Items]                    
Shares issued in IPO (shares)                 450,000us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_SubsequentEventTypeAxis
= us-gaap_SubsequentEventMember
/ us-gaap_SubsidiarySaleOfStockAxis
= us-gaap_OverAllotmentOptionMember
/ us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis
= us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
 
Option exercise period             30 days