| Cover Page Cover Page | Nov. 21, 2019 |
| Cover page. | |
| Document Type | 8-K |
| Document Period End Date | Nov. 21, 2019 |
| Entity Registrant Name | EMERGENT BIOSOLUTIONS INC. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-33137 |
| Entity Tax Identification Number | 14-1902018 |
| Entity Address, Address Line One | 400 Professional Drive |
| Entity Address, Address Line Two | Suite 400 |
| Entity Address, City or Town | Gaithersburg |
| Entity Address, State or Province | MD |
| Entity Address, Postal Zip Code | 20879 |
| City Area Code | 240 |
| Local Phone Number | 631-3200 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Title of 12(b) Security | Common Stock, Par Value $0.001 per share |
| Trading Symbol | EBS |
| Security Exchange Name | NYSE |
| Entity Central Index Key | 0001367644 |
| Amendment Flag | false |
