Segment information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Segment Reporting Information [Line Items]
Number of business segments			2
External revenue	$ 70,379	$ 88,141	$ 120,690	$ 106,674
Net income (loss) attributable to Emergent BioSolutions Inc.	7,632	14,210	800	(7,187)
Total assets	527,140	493,984	527,140	493,984	546,864
Biodefense [Member]
Segment Reporting Information [Line Items]
External revenue	66,964	83,685	115,600	99,185
Net income (loss) attributable to Emergent BioSolutions Inc.	24,335	36,902	38,601	30,810
Total assets	257,377	217,057	257,377	217,057
Biosciences [Member]
Segment Reporting Information [Line Items]
External revenue	3,415	4,456	5,090	7,489
Net income (loss) attributable to Emergent BioSolutions Inc.	(14,963)	(20,580)	(34,854)	(35,705)
Total assets	129,565	121,209	129,565	121,209
All Other [Member]
Segment Reporting Information [Line Items]
External revenue	0	0	0	0
Net income (loss) attributable to Emergent BioSolutions Inc.	(1,740)	(2,112)	(2,947)	(2,292)
Total assets	$ 140,198	$ 155,718	$ 140,198	$ 155,718