| Cover Page Cover Page | Jan. 10, 2021 | Nov. 05, 2020 | Jan. 13, 2020 |
| Cover [Abstract] | |||
| Document Type | 8-K | ||
| Document Period End Date | Jan. 10, 2021 | ||
| 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 |
