Stock-Based Compensation - Allocated Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 10,606	$ 9,978	$ 33,921	$ 29,015
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	7,041	6,682	23,253	20,022
Pre-approval commercial manufacturing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	807	700	2,490	1,804
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 2,758	$ 2,596	$ 8,178	$ 7,189