v3.6.0.2
Document and Entity Information - USD ($)
$ in Billions
12 Months Ended
Dec. 31, 2016
Jan. 31, 2017
Jun. 30, 2016
Document And Entity Information [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2016    
Document Fiscal Year Focus 2016    
Document Fiscal Period Focus FY    
Trading Symbol ACAD    
Entity Registrant Name ACADIA PHARMACEUTICALS INC    
Entity Central Index Key 0001070494    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer Yes    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Large Accelerated Filer    
Entity Common Stock, Shares Outstanding   121,407,626  
Entity Public Float     $ 2.3