Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2015

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:

	Year Ended December 31,
	2015		2014		2013
Bayer Pharma, AG and Janssen Pharmaceuticals, Inc.		48%		37%		37%
Daiichi Sankyo, Inc.		38%		45%		23%
Bristol-Myers Squibb Company and Pfizer Inc.		13%		16%		38%