U.S. Government Agreement, Joint Venture and Collaborations (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended				1 Months Ended	9 Months Ended	19 Months Ended	32 Months Ended	1 Months Ended		1 Months Ended	9 Months Ended	15 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Feb. 28, 2011	Sep. 30, 2013 Cadila [Member]	Feb. 28, 2011 HHS BARDA Contract [Member]	Sep. 30, 2013 HHS BARDA Contract [Member]	Sep. 30, 2013 HHS BARDA Contract [Member]	Sep. 30, 2013 HHS BARDA Contract [Member]	Feb. 28, 2011 HHS BARDA Option for Additional Period [Member]	Feb. 28, 2011 License Agreement with LG Life Sciences, Ltd. [Member]	Jul. 31, 2012 PATH Vaccine Solutions [Member]	Sep. 30, 2013 PATH Vaccine Solutions [Member]	Sep. 30, 2013 PATH Vaccine Solutions [Member]	Aug. 31, 2013 PATH Vaccine Solutions [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Contract receivable					$ 179,000		$ 97,000				$ 82,000
Contract term							3 years				2 years
Government contracts	4,268	5,583	10,985	17,328				10,700		45,000
Research and development collaborations	534	182	1,182	182									2,000	700	2,000
Research and development collaboration increase																400
Trial costs incurred									2,900
Upfront license payment												$ 2,500
Ownership percentage	20.00%		20.00%
Joint Venture Percentage Owned By Others						80.00%