REVENUE (Details) (USD $)	12 Months Ended						1 Months Ended	12 Months Ended			1 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Collaboration arrangement for development and commercialization of oral rotavirus strain Glaxo Rotarix	Dec. 31, 2011 Collaboration arrangement for development and commercialization of oral rotavirus strain Glaxo Rotarix	Dec. 31, 2010 Collaboration arrangement for development and commercialization of oral rotavirus strain Glaxo Rotarix	Apr. 30, 2008 Collaboration arrangement for development and commercialization of oral rotavirus strain Pfizer Rindopepimut	Dec. 31, 2010 Collaboration arrangement for development and commercialization of oral rotavirus strain Pfizer Rindopepimut	Dec. 31, 1995 License agreements Cincinnati Children's Hospital Medical Center Rotarix	Dec. 31, 2010 License agreements Duke University and Thomas Jefferson University Rindopepimut	May 31, 2005 Royalty Agreement PRF Rotarix	Dec. 31, 2012 Royalty Agreement PRF Rotarix Subsequent event
REVENUE
Percentage of license fee payable on net royalties received									30.00%
Percentage of interest in net royalties sold											70.00%
Period for right to negotiate to extend the agreement term												120 days
Product royalty revenue	$ 10,775,000	$ 9,119,000	$ 6,386,000	$ 10,800,000	$ 9,100,000	$ 6,400,000
Product royalty expense	10,775,000	9,119,000	12,077,000	10,800,000	9,100,000	6,400,000		5,700,000
Upfront fee received							40,000,000
Equity investment							10,000,000
Product development and licensing agreement revenue	146,000	110,000	40,187,000					39,900,000
Reimbursable costs								800,000
Sublicense fees paid to Duke University and Thomas Jefferson University										$ 6,900,000