Employee and Consultant Equity-Based Compensation - Equity-Based Compensation Expense and Tax Benefit (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Equity-based compensation expense	$ 1,686	$ 1,657
Unrecognized equity-based compensation cost	13,200
Unrecognized equity-based compensation cost, restricted stock units	579
Research and development
Equity-based compensation expense	202	688
Sales, general and administrative
Equity-based compensation expense	$ 1,484	$ 969