Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 85,705	$ 85,573	$ 172,215	$ 168,203
U.S.
Disaggregation of Revenue [Line Items]
Revenues	75,190	74,086	150,624	145,574
U.S. | Product revenue, net
Disaggregation of Revenue [Line Items]
Revenues	75,190	74,086	150,624	145,574
U.S. | License and royalty revenues
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
International
Disaggregation of Revenue [Line Items]
Revenues	10,515	11,487	21,591	22,629
International | Product revenue, net
Disaggregation of Revenue [Line Items]
Revenues	9,987	10,918	20,536	21,498
International | License and royalty revenues
Disaggregation of Revenue [Line Items]
Revenues	$ 528	$ 569	$ 1,055	$ 1,131