XML 28 R61.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Stockholders' Equity (Details Textual) (USD $) | 12 Months Ended | 0 Months Ended |
--- | --- | --- | ---
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | May 31, 2012 | May 29, 2009 | Aug. 31, 2014
Employee Stock Purchase Plan [Abstract] |  |  |  |  |  |
Stock-based compensation expense | $ 11,270,000us-gaap_ShareBasedCompensation | $ 5,666,000us-gaap_ShareBasedCompensation | $ 4,067,000us-gaap_ShareBasedCompensation |  |  |
Preferred Stock [Abstract] |  |  |  |  |  |
Preferred stock authorized (shares) | 5,000,000us-gaap_PreferredStockSharesAuthorized |  |  |  |  |
Shareholder Rights Plan and Warrants [Abstract] |  |  |  |  |  |
Exercise price per share of warrants |  |  |  |  |  | $ 125.08us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Warrants to purchase number of shares |  |  |  |  |  | 3,264,643us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
Public Offering [Abstract] |  |  |  |  |  |
Common Stock, Shares, Issued | 19,575,150us-gaap_CommonStockSharesIssued | 20,468,521us-gaap_CommonStockSharesIssued |  |  |  |
Proceeds from issuance of common stock, net | 0us-gaap_ProceedsFromIssuanceOfCommonStock | 0us-gaap_ProceedsFromIssuanceOfCommonStock | 5,313,000us-gaap_ProceedsFromIssuanceOfCommonStock |  |  |
Corporate Share Repurchase [Abstract] |  |  |  |  |  |
Stock Repurchase Program, Authorized Amount |  |  |  |  |  | 200,000,000.0us-gaap_StockRepurchaseProgramAuthorizedAmount1
Stock Repurchased During Period, Shares | 1,253,425us-gaap_StockRepurchasedDuringPeriodShares |  |  |  |  |
Treasury Stock Acquired, Average Cost Per Share | $ 54.20us-gaap_TreasuryStockAcquiredAverageCostPerShare |  |  |  |  |
Stock Repurchased During Period, Value | 67,955,000us-gaap_StockRepurchasedDuringPeriodValue |  |  |  |  |
Public Offering |  |  |  |  |  |
Public Offering [Abstract] |  |  |  |  |  |
Common Stock, Shares, Issued | 0us-gaap_CommonStockSharesIssued / lgnd_EquityAxis = lgnd_PublicOfferingMember | 302,750us-gaap_CommonStockSharesIssued / lgnd_EquityAxis = lgnd_PublicOfferingMember |  |  |  |
Stock issued, weighted average price per share |  | $ 18.87us-gaap_SharePrice / lgnd_EquityAxis = lgnd_PublicOfferingMember |  |  |  |
At the Market Equity Offering Program |  |  |  |  |  |
Public Offering [Abstract] |  |  |  |  |  |
Proceeds from issuance of common stock, net |  | 5,500,000us-gaap_ProceedsFromIssuanceOfCommonStock / lgnd_EquityAxis = lgnd_AttheMarketEquityOfferingProgramMember |  |  |  |
2006 Stockholder Rights Plan |  |  |  |  |  |
Shareholder Rights Plan and Warrants [Abstract] |  |  |  |  |  |
Number of rights per outstanding share of common stock | 1lgnd_ClassOfWarrantOrRightDividendDistributionNumberOfRightsPerOutstandingShareOfCommonStock / us-gaap_ClassOfWarrantOrRightAxis = lgnd_TwoThousandSixStockholderRightsPlanMember |  |  |  |  |
Exercise price per share of warrants | $ 100us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1 / us-gaap_ClassOfWarrantOrRightAxis = lgnd_TwoThousandSixStockholderRightsPlanMember |  |  |  |  |
Percentage acquisition of company's common stock causing warrants or rights to become exercisable | 20.00%lgnd_ClassOfWarrantOrRightPercentageAcquistionOfCompanysCommonStockCausingWarrantsOrRightsToBecomeExercisable / us-gaap_ClassOfWarrantOrRightAxis = lgnd_TwoThousandSixStockholderRightsPlanMember |  |  |  |  |
Percentage acquisition of company's common stock from tender offer causing warrants or rights to become exercisable | 20.00%lgnd_ClassOfWarrantOrRightPercentageAcquistionOfCompanysCommonStockFromTenderOfferCausingWarrantsOrRightsToBecomeExercisable / us-gaap_ClassOfWarrantOrRightAxis = lgnd_TwoThousandSixStockholderRightsPlanMember |  |  |  |  |
Business combination, acquiring person discount (percent) | 50.00%lgnd_ClassOfWarrantOrRightBusinessCombinationAcquiringPersonDiscount / us-gaap_ClassOfWarrantOrRightAxis = lgnd_TwoThousandSixStockholderRightsPlanMember |  |  |  |  |
Warrants to purchase number of shares | 0.001us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights / us-gaap_ClassOfWarrantOrRightAxis = lgnd_TwoThousandSixStockholderRightsPlanMember |  |  |  |  |
Warrants to purchase shares, stockholder other than acquiring person, exercise price percentage | 200.00%lgnd_ClassOfWarrantOrRightExercisePricePercentageInEventRightsPermitStockholderOtherThanAcquiringPersonToPurchase / us-gaap_ClassOfWarrantOrRightAxis = lgnd_TwoThousandSixStockholderRightsPlanMember |  |  |  |  |
Series A Preferred Stock |  |  |  |  |  |
Preferred Stock [Abstract] |  |  |  |  |  |
Preferred stock authorized (shares) | 1,600,000us-gaap_PreferredStockSharesAuthorized / us-gaap_StatementClassOfStockAxis = us-gaap_SeriesAPreferredStockMember |  |  |  |  |
Stock Options |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Weighted-average grant date fair value per share of stock options | $ 46.20us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockOptionMember | $ 14.28us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockOptionMember | $ 9.13us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockOptionMember |  |  |
Intrinsic value of options exercised | 15,300,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockOptionMember | 5,900,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockOptionMember | 500,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockOptionMember |  |  |
Unrecognized compensation cost | 13,200,000us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockOptionMember |  |  |  |  |
Weighted-average period in which cost is expected to be recognized | 2 years 2 months 9 days |  |  |  |  |
Restricted Stock |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Award vesting period | 3 years |  |  |  |  |
Weighted-average period in which cost is expected to be recognized | 1 year 3 months 11 days |  |  |  |  |
Unrecognized compensation cost, restricted stock | 1,900,000us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions / us-gaap_AwardTypeAxis = us-gaap_RestrictedStockMember |  |  |  |  |
2002 Stock Incentive Plan | Director |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Award vesting period | 1 year |  |  |  |  |
2002 Stock Incentive Plan | Stock Options |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Increase the number of shares under the 2002 Stock Incentive Plan |  |  |  | 1,800,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockOptionMember / us-gaap_PlanNameAxis = lgnd_TwoThousandTwoStockIncentivePlanMember | 1,300,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockOptionMember / us-gaap_PlanNameAxis = lgnd_TwoThousandTwoStockIncentivePlanMember |
Shares available for future option grants | 1,100,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockOptionMember / us-gaap_PlanNameAxis = lgnd_TwoThousandTwoStockIncentivePlanMember |  |  |  |  |
Award expiration period | 10 years |  |  |  |  |
2002 Stock Incentive Plan | Stock Options | Vest 1/8 on the six month anniversary of the date of grant |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Award vesting period | 6 months |  |  |  |  |
Award vesting right percentage | 12.50%us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockOptionMember / us-gaap_PlanNameAxis = lgnd_TwoThousandTwoStockIncentivePlanMember / us-gaap_VestingAxis = lgnd_VestingPeriodOneMember |  |  |  |  |
2002 Stock Incentive Plan | Stock Options | Vest 1/48 each month for forty-two months |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Award vesting period | 42 months |  |  |  |  |
Award vesting right percentage | 2.08%us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockOptionMember / us-gaap_PlanNameAxis = lgnd_TwoThousandTwoStockIncentivePlanMember / us-gaap_VestingAxis = lgnd_VestingPeriodTwoMember |  |  |  |  |
Employee Stock Purchase Plan |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Award expiration period | 6 months |  |  |  |  |
Employee Stock Purchase Plan [Abstract] |  |  |  |  |  |
Shares allowed to purchase in employee stock purchase plan | 1,250us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesPerEmployee / us-gaap_PlanNameAxis = us-gaap_EmployeeStockMember |  |  |  |  |
Offering period of shares in employee stock purchase plan | 6 months |  |  |  |  |
Percentage lesser of fair market value taken as purchase price of share | 85.00%lgnd_PercentageOfPurchasePriceOfStock / us-gaap_PlanNameAxis = us-gaap_EmployeeStockMember |  |  |  |  |
Discount rate | 15.00%lgnd_DiscountRate / us-gaap_PlanNameAxis = us-gaap_EmployeeStockMember |  |  |  |  |
Common stock issued under amended ESSP (shares) | 3,774us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod / us-gaap_PlanNameAxis = us-gaap_EmployeeStockMember | 5,016us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod / us-gaap_PlanNameAxis = us-gaap_EmployeeStockMember | 10,763us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod / us-gaap_PlanNameAxis = us-gaap_EmployeeStockMember |  |  |
Stock-based compensation expense | 54,000us-gaap_ShareBasedCompensation / us-gaap_PlanNameAxis = us-gaap_EmployeeStockMember | 45,000us-gaap_ShareBasedCompensation / us-gaap_PlanNameAxis = us-gaap_EmployeeStockMember | 38,000us-gaap_ShareBasedCompensation / us-gaap_PlanNameAxis = us-gaap_EmployeeStockMember |  |  |
Revenue volatility (percent) | 40.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate / us-gaap_PlanNameAxis = us-gaap_EmployeeStockMember | 36.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate / us-gaap_PlanNameAxis = us-gaap_EmployeeStockMember | 34.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate / us-gaap_PlanNameAxis = us-gaap_EmployeeStockMember |  |  |
Shares issued under employee stock purchase plan | 212,447us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber / us-gaap_PlanNameAxis = us-gaap_EmployeeStockMember |  |  |  |  |
Shares available for future purchases | 75,741us-gaap_EmployeeServiceShareBasedCompensationEstimatedQuantityOfSharesToBeRepurchasedInFollowingPeriod / us-gaap_PlanNameAxis = us-gaap_EmployeeStockMember |  |  |  |  |
Employee Stock Purchase Plan | Stock Options |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Cash received from options exercised | $ 4,400,000us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockOptionMember / us-gaap_PlanNameAxis = us-gaap_EmployeeStockMember | $ 3,000,000us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockOptionMember / us-gaap_PlanNameAxis = us-gaap_EmployeeStockMember | $ 1,000,000us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions / us-gaap_AwardTypeAxis = us-gaap_EmployeeStockOptionMember / us-gaap_PlanNameAxis = us-gaap_EmployeeStockMember |  |  |

X
- Definition Class of Warrant or Right, Business Combination, Acquiring Person Discount + References No definition available. + Details
Name: | lgnd_ClassOfWarrantOrRightBusinessCombinationAcquiringPersonDiscount
Namespace Prefix: | lgnd_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Class of Warrant or Right, Dividend Distribution, Number of Rights per Outstanding Share of Common Stock + References No definition available. + Details
Name: | lgnd_ClassOfWarrantOrRightDividendDistributionNumberOfRightsPerOutstandingShareOfCommonStock
Namespace Prefix: | lgnd_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Class of Warrant or Right, Exercise Price Percentage in Event Rights Permit Stockholder Other Than Acquiring Person to Purchase + References No definition available. + Details
Name: | lgnd_ClassOfWarrantOrRightExercisePricePercentageInEventRightsPermitStockholderOtherThanAcquiringPersonToPurchase
Namespace Prefix: | lgnd_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Class of Warrant or Right, Percentage Acquistion of Company's Common Stock Causing Warrants or Rights to Become Exercisable + References No definition available. + Details
Name: | lgnd_ClassOfWarrantOrRightPercentageAcquistionOfCompanysCommonStockCausingWarrantsOrRightsToBecomeExercisable
Namespace Prefix: | lgnd_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Class of Warrant or Right, Percentage Acquistion of Company's Common Stock From Tender Offer Causing Warrants or Rights to Become Exercisable + References No definition available. + Details
Name: | lgnd_ClassOfWarrantOrRightPercentageAcquistionOfCompanysCommonStockFromTenderOfferCausingWarrantsOrRightsToBecomeExercisable
Namespace Prefix: | lgnd_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | lgnd_CorporateShareRepurchaseAbstract
Namespace Prefix: | lgnd_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Discount rate. + References No definition available. + Details
Name: | lgnd_DiscountRate
Namespace Prefix: | lgnd_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | lgnd_EmployeeStockPurchasePlanAbstract
Namespace Prefix: | lgnd_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of purchase price of stock. + References No definition available. + Details
Name: | lgnd_PercentageOfPurchasePriceOfStock
Namespace Prefix: | lgnd_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | lgnd_PublicOfferingAbstract
Namespace Prefix: | lgnd_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Share based compensation arrangement by share based payment award length of each offering. + References No definition available. + Details
Name: | lgnd_ShareBasedCompensationArrangementByShareBasedPaymentAwardLengthOfEachOffering
Namespace Prefix: | lgnd_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | lgnd_ShareholderRightsPlanAndWarrantsAbstract
Namespace Prefix: | lgnd_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Exercise price per share or per unit of warrants or rights outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)(4)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
Name: | us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)(2)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph i -Subparagraph 2 -Article 4 + Details
Name: | us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 30 -Article 5 + Details
Name: | us-gaap_CommonStockSharesIssued
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of shares to be repurchased in accordance with a policy to use treasury stock to satisfy share-award conversions. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (l) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationEstimatedQuantityOfSharesToBeRepurchasedInFollowingPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation. + References No definition available. + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Unrecognized cost of unvested options awarded to employees as compensation. + References No definition available. + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_PreferredStockNumberOfSharesParValueAndOtherDisclosuresAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.28) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29 -Article 5 + Details
Name: | us-gaap_PreferredStockSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The cash inflow from the additional capital contribution to the entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfCommonStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The total cash inflow associated with the amount received from holders to acquire the entity's shares under incentive and share awards, including stock option exercises. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585 + Details
Name: | us-gaap_ShareBasedCompensation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of vesting of share-based compensation awards. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(ii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The highest quantity of shares an employee can purchase under the plan per period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumNumberOfSharesPerEmployee
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of equity instruments other than options outstanding, including both vested and non-vested instruments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(ii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of additional shares authorized for issuance under an established share-based compensation plan. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- 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. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of share instruments newly issued under a share-based compensation plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Price of a single share of a number of saleable stocks of a company. + References No definition available. + Details
Name: | us-gaap_SharePrice
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30 -Article 5 + Details
Name: | us-gaap_StockRepurchasedDuringPeriodShares
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30, 31 -Article 5 + Details
Name: | us-gaap_StockRepurchasedDuringPeriodValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of stock repurchase plan authorized. + References No definition available. + Details
Name: | us-gaap_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Total cost of shares repurchased divided by the total number of shares repurchased. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655 + Details
Name: | us-gaap_TreasuryStockAcquiredAverageCostPerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | lgnd_EquityAxis=lgnd_AttheMarketEquityOfferingProgramMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | lgnd_EquityAxis=lgnd_PublicOfferingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_RestrictedStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ClassOfWarrantOrRightAxis=lgnd_TwoThousandSixStockholderRightsPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=lgnd_TwoThousandTwoStockIncentivePlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=us-gaap_EmployeeStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=us-gaap_SeriesAPreferredStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |