Annual report pursuant to Section 13 and 15(d)

Document and Entity Information

v2.4.1.9
Document and Entity Information (USD $)
In Billions, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Feb. 17, 2015
Jun. 30, 2014
Document and Entity Information [Abstract]      
Entity Registrant Name LIGAND PHARMACEUTICALS INC    
Entity Central Index Key 0000886163    
Document Type 10-K    
Document Period End Date Dec. 31, 2014    
Amendment Flag false    
Document Fiscal Year Focus 2014    
Document Fiscal Period Focus FY    
Current Fiscal Year End Date --12-31    
Entity Filer Category Large Accelerated Filer    
Entity Common Stock, Shares Outstanding   19,577,556dei_EntityCommonStockSharesOutstanding  
Entity Public Float     $ 1.0dei_EntityPublicFloat
Entity Voluntary Filers No    
Entity Well-known Seasoned Issuer No    
Entity Current Reporting Status Yes