Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Net revenue	$ 62,197	$ 61,303
U.S.
Disaggregation of Revenue [Line Items]
Net revenue	56,578	54,792
Rest of World
Disaggregation of Revenue [Line Items]
Net revenue	5,619	6,511
Drug Revenues
Disaggregation of Revenue [Line Items]
Net revenue	1,136	545
Drug Revenues | U.S.
Disaggregation of Revenue [Line Items]
Net revenue	910	272
Drug Revenues | Rest of World
Disaggregation of Revenue [Line Items]
Net revenue	226	273
Concentrate Products
Disaggregation of Revenue [Line Items]
Net revenue	61,061	60,758
Concentrate Products | U.S.
Disaggregation of Revenue [Line Items]
Net revenue	55,668	54,520
Concentrate Products | Rest of World
Disaggregation of Revenue [Line Items]
Net revenue	5,393	6,238
Point-in-time | Drug Product Sales
Disaggregation of Revenue [Line Items]
Net revenue	910	272
Point-in-time | Drug Product Sales | U.S.
Disaggregation of Revenue [Line Items]
Net revenue	910	272
Point-in-time | Drug Product Sales | Rest of World
Disaggregation of Revenue [Line Items]
Net revenue	0	0
Point-in-time | Concentrate Product Sales
Disaggregation of Revenue [Line Items]
Net revenue	59,100	58,778
Point-in-time | Concentrate Product Sales | U.S.
Disaggregation of Revenue [Line Items]
Net revenue	53,707	52,540
Point-in-time | Concentrate Product Sales | Rest of World
Disaggregation of Revenue [Line Items]
Net revenue	5,393	6,238
Point-in-time | Concentrate Product License Fee
Disaggregation of Revenue [Line Items]
Net revenue	1,961	1,980
Point-in-time | Concentrate Product License Fee | U.S.
Disaggregation of Revenue [Line Items]
Net revenue	1,961	1,980
Point-in-time | Concentrate Product License Fee | Rest of World
Disaggregation of Revenue [Line Items]
Net revenue	0	0
Over-time | Drug License Fee
Disaggregation of Revenue [Line Items]
Net revenue	226	273
Over-time | Drug License Fee | U.S.
Disaggregation of Revenue [Line Items]
Net revenue	0	0
Over-time | Drug License Fee | Rest of World
Disaggregation of Revenue [Line Items]
Net revenue	$ 226	$ 273