Segment information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Segment Reporting Information [Line Items]
Number of business segments			2
External revenue	$ 66,592	$ 58,762	$ 187,282	$ 165,436
Net income (loss) attributable to Emergent BioSolutions Inc.	6,617	1,549	7,417	(5,638)
Total assets	540,025		540,025		546,864
Biodefense [Member]
Segment Reporting Information [Line Items]
External revenue	66,238	56,679	181,838	155,864
Net income (loss) attributable to Emergent BioSolutions Inc.	20,760	17,326	59,361	46,863
Biosciences [Member]
Segment Reporting Information [Line Items]
External revenue	354	2,083	5,444	9,572
Net income (loss) attributable to Emergent BioSolutions Inc.	(12,165)	(14,260)	(47,019)	(48,691)
All Other [Member]
Segment Reporting Information [Line Items]
External revenue	0	0	0	0
Net income (loss) attributable to Emergent BioSolutions Inc.	$ (1,978)	$ (1,517)	$ (4,925)	$ (3,810)