U.S. Government Contracts (Details Textual) (USD $) In Millions, unless otherwise specified	1 Months Ended	6 Months Ended
	Jul. 31, 2012	Jun. 30, 2012 Segment	Aug. 31, 2012
U.S. Government Contracts (Textual) [Abstract]
Aggregate potential funding		$ 161.5
July 2010 Agreement (Ebola and Marburg) [Member]
U.S. Government Contracts (Textual) [Abstract]
Additional funding available		126.5	100.0
Government revenue billed and recognized		75.0
Number Of Segments		4
Aggregate period of performance spanning		6 years
Aggregate potential funding		288.0	183.0
Aggregate potential funding period		6 years
Total funding award	$ 4.5