Segment information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) Segment BusinessUnit	Jun. 30, 2014 USD ($)
Segment Reporting Information [Line Items]
Number of business segments | Segment			2
External revenue	$ 126,112	$ 110,325	$ 189,745	$ 164,209
Net income (loss)	14,100	5,029	$ (7,419)	(15,207)
Biodefense [Member]
Segment Reporting Information [Line Items]
Number of business units | BusinessUnit			2
External revenue	110,177	91,103	$ 153,804	138,542
Net income (loss)	35,376	22,416	$ 24,055	23,828
Biosciences [Member]
Segment Reporting Information [Line Items]
Number of business units | BusinessUnit			3
External revenue	15,935	19,222	$ 35,941	25,667
Net income (loss)	(19,301)	(15,001)	(27,319)	(34,510)
All Other [Member]
Segment Reporting Information [Line Items]
External revenue	0	0	0	0
Net income (loss)	$ (1,975)	$ (2,386)	$ (4,155)	$ (4,525)