Document and Entity Information (USD $)
In Millions, except Share data, unless otherwise specified
 12 Months Ended
Dec. 31, 2014
Mar. 05, 2015
Jun. 30, 2014
Document and Entity Information      
Entity Registrant Name Radius Health, Inc.    
Entity Central Index Key 0001428522    
Document Type 10-K    
Document Period End Date Dec. 31, 2014    
Amendment Flag false    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Filer Category Accelerated Filer    
Entity Public Float     $ 190.5
Entity Common Stock, Shares Outstanding   37,821,722  
Document Fiscal Year Focus 2014    
Document Fiscal Period Focus FY