| Document and Entity Information | May 24, 2021 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001634432 |
| Document Type | 8-K |
| Document Period End Date | May 24, 2021 |
| Entity Registrant Name | STRONGBRIDGE BIOPHARMA plc |
| Entity Incorporation State Country Code | L2 |
| Entity File Number | 001-37569 |
| Entity Tax Identification Number | 98-1275166 |
| Entity Address, Address Line One | 900 Northbrook Drive |
| Entity Address, Address Line Two | Suite 200 |
| Entity Address, City or Town | Trevose |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 19053 |
| City Area Code | (610) |
| Local Phone Number | 254-9200 |
| Written Communications | true |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Ordinary Share, par value $0.01 per share |
| Trading Symbol | SBBP |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
