Equity-Based Compensation - Equity-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Equity-based compensation expense
Total equity-based compensation expense	$ 19,949	$ 20,296	$ 19,576
Income tax effect	0	(6,188)	(5,696)
After-tax effect of equity-based compensation expense	19,949	14,108	13,880
Cost of product sales
Equity-based compensation expense
Total equity-based compensation expense	802	884	511
Research and development
Equity-based compensation expense
Total equity-based compensation expense	2,533	3,225	3,475
Selling, general and administrative
Equity-based compensation expense
Total equity-based compensation expense	$ 16,614	$ 16,187	$ 15,590