Document and Entity Information - shares
3 Months Ended
Mar. 31, 2019
Apr. 29, 2019
Document and Entity Information [Abstract]    
Entity Registrant Name Strongbridge Biopharma plc  
Entity Central Index Key 0001634432  
Document Type 10-Q  
Current Fiscal Year End Date --12-31  
Document Period End Date Mar. 31, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q1  
Amendment Flag false  
Entity Current Reporting Status Yes  
Entity Filer Category Accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company true  
Entity Ex Transition Period true  
Entity Common Stock, Shares Outstanding   54,172,061