Equity-Based Compensation (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Equity-based compensation expense
Total equity-based compensation expense	$ 1,930	$ 2,283
Cost of product sales
Equity-based compensation expense
Total equity-based compensation expense	28	23
Research and development
Equity-based compensation expense
Total equity-based compensation expense	449	932
Selling, general and administrative
Equity-based compensation expense
Total equity-based compensation expense	$ 1,453	$ 1,328