Variable interest entities (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Variable Interest Entity [Line Items]
Net loss	$ 5,620,000	$ (137,000)	$ 3,141,000	$ (10,787,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity beginning of period			416,727,000
Non-cash development expenses from variable interest entities			3,163,000
Net income (loss)	5,620,000	(137,000)	3,141,000	(10,787,000)
Other			5,381,000
Stockholders' equity end of period	428,412,000		428,412,000
Emergent BioSolutions Inc. [Member]
Variable Interest Entity [Line Items]
Net loss			7,417,000
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)			7,417,000
Other			5,381,000
Stockholders' equity end of period	427,044,000		427,044,000
Noncontrolling Interests [Member]
Variable Interest Entity [Line Items]
Net loss			(4,276,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity beginning of period			2,481,000
Non-cash development expenses from variable interest entities			3,163,000
Net income (loss)			(4,276,000)
Other			0
Stockholders' equity end of period	1,368,000		1,368,000
Oxford-Emergent Tuberculosis Consortium [Member]
Variable Interest Entity [Line Items]
Ownership percentage of variable interest entity (in hundredths)			51.00%
Assets	1,600,000	408,000	1,600,000	408,000
Liabilities	2,800,000	532,000	2,800,000	532,000
OETC Loan	4,000,000		4,000,000
Net loss	2,000,000	3,100,000	8,500,000	9,900,000
Net losses included in the Company's consolidated statement of operations	1,000,000	1,600,000	4,300,000	5,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	2,000,000	3,100,000	8,500,000	9,900,000
EPIC Bio Pte Ltd [Member]
Variable Interest Entity [Line Items]
Ownership percentage of variable interest entity (in hundredths)			60.00%
Assets	349,000	1,600,000	349,000	1,600,000
Liabilities	168,000	830,000	168,000	830,000
Net loss	45,000	407,000	255,000	783,000
Net losses included in the Company's consolidated statement of operations	27,000	244,000	153,000	470,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 45,000	$ 407,000	$ 255,000	$ 783,000