Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Revenues	$ 88,900	$ 79,941	$ 257,103	$ 250,137
Product revenue, net
Disaggregation of Revenue [Line Items]
Revenues	88,324		255,396
License and royalty revenues
Disaggregation of Revenue [Line Items]
Revenues	576		1,707
U.S.
Disaggregation of Revenue [Line Items]
Revenues	70,255	69,579	215,829	218,706
U.S. | Product revenue, net
Disaggregation of Revenue [Line Items]
Revenues	70,255		215,829
U.S. | License and royalty revenues
Disaggregation of Revenue [Line Items]
Revenues	0		0
International
Disaggregation of Revenue [Line Items]
Revenues	18,645	$ 10,362	41,274	$ 31,431
International | Product revenue, net
Disaggregation of Revenue [Line Items]
Revenues	18,069		39,567
International | License and royalty revenues
Disaggregation of Revenue [Line Items]
Revenues	$ 576		$ 1,707