Annual report pursuant to Section 13 and 15(d)

Document And Entity Information

v2.4.0.6
Document And Entity Information (USD $)
In Millions, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2011
Feb. 01, 2012
Jun. 30, 2011
Document And Entity Information [Abstract]      
Document Type 10-K    
Amendment Flag false    
Entity Central Index Key 0000886163    
Entity Registrant Name LIGAND PHARMACEUTICALS INC    
Current Fiscal Year End Date --12-31    
Document Period End Date Dec. 31, 2011    
Document Fiscal Year Focus 2011    
Document Fiscal Period Focus FY    
Entity Filer Category Accelerated Filer    
Entity Common Stock, Shares Outstanding   19,683,235  
Entity Public Float     $ 206.6
Entity Voluntary Filers No    
Entity Well-known Seasoned Issuer No    
Entity Current Reporting Status Yes