Commitments and Contingencies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Future minimum lease payments under non-cancelable operating leases
2016	$ 3,716
2017	3,447
2018	2,636
2019	498
2020	237
Total	10,534
Total rent expense	3,800	$ 3,600	$ 3,500
Future milestone payments under Assignment and License Agreements
2016	6,136
2017	4,640
2018	3,705
2019	9,711
2020	1,759
Thereafter	7,070
Total	$ 33,021