Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

v2.4.0.8
Document and Entity Information
6 Months Ended
Jun. 30, 2013
Aug. 01, 2013
Document and Entity Information [Abstract]    
Entity Registrant Name LIGAND PHARMACEUTICALS INC  
Entity Central Index Key 0000886163  
Document Type 10-Q  
Document Period End Date Jun. 30, 2013  
Amendment Flag false  
Document Fiscal Year Focus 2013  
Document Fiscal Period Focus Q2  
Current Fiscal Year End Date --12-31  
Entity Filer Category Accelerated Filer  
Entity Common Stock, Shares Outstanding   20,440,863