Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2014

Accounting Policies [Abstract]

Percentage of Revenue from Significant Customers

Customers who accounted for 10% or more of total revenues were as follows:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2014			2013			2014			2013
Bristol-Myers Squibb Company and Pfizer Inc.		7	%		28	%		15	%		46	%
Bayer Pharma, AG and Janssen Pharmaceuticals, Inc.		28	%		37	%		39	%		41	%
Daiichi Sankyo, Inc.		63	%		32	%		43	%		12	%