Variable interest entities (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Variable Interest Entity [Line Items]
Net loss	$ 5,546,000	$ 12,523,000	$ (2,479,000)	$ (10,650,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity beginning of period			416,727,000
Non-cash development expenses from variable interest entities			3,632,000
Net income (loss)	5,546,000	12,523,000	(2,479,000)	(10,650,000)
Other			4,642,000
Stockholders' equity end of period	422,522,000		422,522,000
Emergent BioSolutions Inc. [Member]
Variable Interest Entity [Line Items]
Net loss			800,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity beginning of period			414,246,000
Non-cash development expenses from variable interest entities			0
Net income (loss)			800,000
Other			4,642,000
Stockholders' equity end of period	419,688,000		419,688,000
Noncontrolling Interests [Member]
Variable Interest Entity [Line Items]
Net loss			(3,279,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity beginning of period			2,481,000
Non-cash development expenses from variable interest entities			3,632,000
Net income (loss)			(3,279,000)
Other			0
Stockholders' equity end of period	2,834,000		2,834,000
Oxford-Emergent Tuberculosis Consortium [Member]
Variable Interest Entity [Line Items]
Ownership percentage of variable interest entity (in hundredths)			51.00%
Assets	3,500,000	394,000	3,500,000	394,000
Liabilities	5,300,000	910,000	5,300,000	910,000
OETC Loan	4,000,000		4,000,000
Net loss	4,200,000	3,200,000	6,500,000	6,800,000
Net losses included in the Company's consolidated statement of operations	2,100,000	1,600,000	3,300,000	3,400,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	4,200,000	3,200,000	6,500,000	6,800,000
EPIC Bio Pte Ltd [Member]
Variable Interest Entity [Line Items]
Ownership percentage of variable interest entity (in hundredths)			60.00%
Assets	317,000	1,900,000	317,000	1,900,000
Liabilities	99,000	741,000	99,000	741,000
Net loss	111,000	352,000	210,000	375,000
Net losses included in the Company's consolidated statement of operations	67,000	211,000	126,000	225,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 111,000	$ 352,000	$ 210,000	$ 375,000