Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2016

Accounting Policies [Abstract]

Percentage of Revenue from Significant Collaboration Customers

Collaboration customers who accounted for 10% or more of total collaboration and license revenues were as follows:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2016			2015			2016			2015
Daiichi Sankyo, Inc.		41	%		40	%		39	%		45	%
Bayer Pharma, AG and Janssen Pharmaceuticals, Inc.		36	%		45	%		34	%		38	%
Bristol-Myers Squibb Company and Pfizer Inc.		19	%		13	%		22	%		15	%