Collaborations and Contingencies (Details) (USD $)	6 Months Ended	0 Months Ended	1 Months Ended	3 Months Ended		6 Months Ended		0 Months Ended	1 Months Ended	12 Months Ended
	Jun. 30, 2012	May 31, 2012 License agreement Bayer item	Aug. 31, 2010 License agreement Bayer	Jun. 30, 2013 License agreement Bayer	Jun. 30, 2012 License agreement Bayer	Jun. 30, 2013 License agreement Bayer item	Jun. 30, 2012 License agreement Bayer	May 31, 2012 License agreement LA Biomed	Aug. 31, 2005 License agreement LA Biomed	Dec. 31, 2010 License agreement LA Biomed	Aug. 31, 2010 License agreement LA Biomed
Collaboration Arrangements
Upfront license fee paid	$ (3,847,000)		$ 21,319,000
Contingent income			297,000,000
Contingent event-based payment				39,600,000		39,600,000
Contingent income received		15,800,000
Number of consecutive validated manufacturing lots		2
Deferred revenue		21,319,000
Restricted cash		17,400,000	22,247,000
Deferred development funds		17,400,000	22,247,000
Amounts recognized as offsets to research and development expense				2,105,000	3,483,000	5,201,000	6,542,000
Number of territories outside of the European Union						2
Milestone payment									500,000
Non-royalty sublicense fees equal to a certain percentage of sublicense income (as a percent)									10.00%
Maximum non-royalty sublicense fees									5,000,000
Right to issue capital to satisfy payment of sublicense fees (as a percent)									50.00%
Non-royalty sublicense fee expenses								1,580,000			1,950,000
Non-royalty sublicense fee paid										390,000
Remainder of non-royalty sublicense fee										$ 1,560,000
Non-royalty sublicense fee paid in cash upon initial public offering (as a percent)								50.00%
Non-royalty sublicense fee paid in stock upon initial public offering (as a percent)								50.00%