Collaborative Agreements (Details 3) (USD $)	3 Months Ended			22 Months Ended		1 Months Ended		3 Months Ended	22 Months Ended							22 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Lilly	Sep. 30, 2013 Lilly	Sep. 30, 2013 Lilly Sales milestones	Dec. 31, 2011 Lilly Right-to-test agreement	Aug. 31, 2013 Lilly Development and Commercialization License	Sep. 30, 2013 Lilly Development and Commercialization License	Sep. 30, 2013 Lilly Development and Commercialization License	Dec. 31, 2011 Lilly Development and Commercialization License	Dec. 31, 2011 Lilly Development and Commercialization License Maximum	Sep. 30, 2013 Lilly Development and Commercialization License Phase I clinical trial	Dec. 31, 2011 Lilly Development and Commercialization License Development milestones	Dec. 31, 2011 Lilly Development and Commercialization License Regulatory milestones	Dec. 31, 2011 Lilly Development and Commercialization License Sales milestones	Sep. 30, 2013 Lilly Future Technological Improvements	Sep. 30, 2013 Lilly Research Services
Collaborative Agreements disclosures
Term of agreement						3 years
Payments received under collaboration agreement				$ 28,200,000	$ 800,000	$ 20,000,000			$ 23,500,000							$ 600,000	$ 3,300,000
Potential milestone payment receivable											200,500,000	5,000,000	30,500,000
License exercise fee, for second license								2,000,000	2,000,000
License exercise fee, per subsequent license										2,000,000
Potential milestone payments receivable for each subsequent license under agreement											199,000,000		29,000,000	70,000,000	100,000,000
Allocation of fees to deliverables
Estimated utilization period after commercialization			10 years
Discount rate (as a percent)			16.00%
Amount of arrangement consideration included in license and milestone fees	13,167,000	933,000					7,800,000
Estimated term of development and commercialization license								25 years
Remaining arrangement consideration to be recognized as license revenue								$ 15,700,000	$ 15,700,000