Variable interest entities (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Variable Interest Entity [Line Items]
Net loss	$ (8,805,000)	$ (8,022,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity beginning of period	442,128,000
Non-cash development expenses from variable interest entities	190,000
Net Loss	(8,805,000)	(8,022,000)
Other	0
Stockholders' equity end of period	435,805,000
Emergent BioSolutions Inc. [Member]
Variable Interest Entity [Line Items]
Net loss	(8,062,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity beginning of period	441,358,000
Non-cash development expenses from variable interest entities	0
Net Loss	(8,062,000)
Other	2,292,000
Stockholders' equity end of period	435,588,000
Noncontrolling Interests [Member]
Variable Interest Entity [Line Items]
Net loss	(743,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity beginning of period	770,000
Non-cash development expenses from variable interest entities	190,000
Net Loss	(743,000)
Other	0
Stockholders' equity end of period	217,000
Oxford-Emergent Tuberculosis Consortium [Member]
Variable Interest Entity [Line Items]
Assets	1,300,000	506,000
Liabilities	950,000	1,800,000
Net loss	1,500,000	2,400,000
Net losses included in the Company's consolidated statement of operations	771,000	1,200,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Loss	$ 1,500,000	$ 2,400,000