U.S. Government Agreement, Joint Venture and Collaborations (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended				1 Months Ended	3 Months Ended		12 Months Ended	35 Months Ended	1 Months Ended		1 Months Ended	12 Months Ended	18 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Cadila [Member]	Feb. 28, 2011 HHS BARDA Contract [Member]	Dec. 31, 2013 HHS BARDA Contract [Member]	Sep. 30, 2012 HHS BARDA Contract [Member]	Dec. 31, 2013 HHS BARDA Contract [Member]	Dec. 31, 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]	Dec. 31, 2013 PATH Vaccine Solutions [Member]	Dec. 31, 2013 PATH Vaccine Solutions [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Contract receivable					$ 97,000					$ 79,000
Contract term					3 years 7 months					2 years
Government contracts	17,708	20,671	14,688			2,700		17,400	52,000
Research and development collaborations	3,207	1,405										2,000	2,500	3,800
Research and development collaboration increase												400	3,500	3,500
Trial costs incurred							2,900
Upfront license payment											$ 2,500
Joint Venture Percentage Owned By Others	20.00%			80.00%