Stock-Based Compensation (Details 2) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Stock-based compensation
Stock-based compensation expense	$ 1,864	$ 1,933
Stock options
Stock-based compensation
Total unrecognized compensation cost related to unvested stock-based compensation	1,400
RSUs
Stock-based compensation
Total unrecognized compensation cost related to unvested stock-based compensation	1,500
Unvested RSAs
Stock-based compensation
Total unrecognized compensation cost related to unvested stock-based compensation	12,000
Research and development | Continuing operations
Stock-based compensation
Stock-based compensation expense	175	235
General and administrative | Continuing operations
Stock-based compensation
Stock-based compensation expense	$ 1,689	$ 1,698