Concentration of Credit Risk (Tables)

12 Months Ended

Dec. 31, 2015

Concentration of Credit Risk

Schedule of concentration of credit risk related to collaborative partners

	Percentage of Total
	Contract Revenues for the
	Years Ended,
	December 31,
	2015		2014		2013
	(in millions)
Collaboration Partner A	83	%	88	%	86	%
Collaboration Partner B	17	%	12	%	14	%

Schedule of concentration of credit risk related to specialty pharmacy customers

	Percentage of Total Net
	Product Revenues for the
	Years Ended,
	December 31,
	2015		2014		2013
	(in millions)
Customer A	28	%	29	%	29	%
Customer B	19	%	22	%	17	%
Customer C	13	%	10	%	11	%
Customer D	9	%	9	%	11	%