Equity-Based Compensation (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Equity-based compensation expense
Total equity-based compensation expense	$ 1,939	$ 1,577	$ 4,221	$ 3,262
Cost of product sales
Equity-based compensation expense
Total equity-based compensation expense	35	68	58	146
Research and development
Equity-based compensation expense
Total equity-based compensation expense	365	525	1,297	947
Selling, general and administrative
Equity-based compensation expense
Total equity-based compensation expense	$ 1,539	$ 984	$ 2,866	$ 2,169