Equity-Based Compensation (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Equity-based compensation expense
Total equity-based compensation expense	$ 2,283	$ 1,685
Cost of product sales
Equity-based compensation expense
Total equity-based compensation expense	23	78
Research and development
Equity-based compensation expense
Total equity-based compensation expense	932	422
Selling, general and administrative
Equity-based compensation expense
Total equity-based compensation expense	$ 1,328	$ 1,185