Collaborative Arrangements (Details 4) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Information related to collaborative arrangements
Total reduction to R&D expense	$ 133	$ 2,134
GSK
Information related to collaborative arrangements
Total reduction to R&D expense	43	171
Merck
Information related to collaborative arrangements
Total reduction to R&D expense	0	1,429
Alfa Wassermann
Information related to collaborative arrangements
Total reduction to R&D expense	72	208
R-Pharm
Information related to collaborative arrangements
Total reduction to R&D expense	$ 18	$ 326