Equity-Based Compensation - Equity-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Equity-based compensation expense
Total equity-based compensation expense	$ 4,792	$ 5,005	$ 9,583	$ 9,735
Income tax effect	835	(1,529)	0	(2,895)
After-tax effect of equity-based compensation expense	5,627	3,476	9,583	6,840
Cost of product sales
Equity-based compensation expense
Total equity-based compensation expense	107	129	307	258
Research and development
Equity-based compensation expense
Total equity-based compensation expense	608	1,095	1,328	1,851
Selling, general and administrative
Equity-based compensation expense
Total equity-based compensation expense	$ 4,077	$ 3,781	$ 7,948	$ 7,626