| Component: (Network and Table) | |
|---|---|
| Network | 00090 - Document - Document And Entity Information (http://www.arenapharm.com/2011-06-30/role/DocumentDocumentAndEntityInformation) |
| Table | (Implied) |
| Reporting Entity [Axis] | 0001080709 (http://www.sec.gov/CIK) |
| Document And Entity Information [Abstract] | Period [Axis] | ||
|---|---|---|---|
2011-01-01 - 2011-12-31 | 2012-03-09 | 2011-06-30 | |
Document And Entity Information [Abstract] | |||
Document Type | 10-K | ||
Amendment Flag | false | ||
Document Period End Date | 2011-12-31 | ||
Document Fiscal Year Focus | 2011 | ||
Document Fiscal Period Focus | FY | ||
Entity Registrant Name | ARENA PHARMACEUTICALS INC | ||
Entity Central Index Key | 0001080709 | ||
Entity Filer Category | Accelerated Filer | ||
Current Fiscal Year End Date | --12-31 | ||
Entity Common Stock, Shares Outstanding | 180,422,401 | ||
Entity Well-known Seasoned Issuer | No | ||
Entity Voluntary Filers | No | ||
Entity Current Reporting Status | Yes | ||
Entity Public Float | 196,900,000 | ||