Company Operations by Product, Customer and Geographic Area - Revenue by Significant Customer (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Total revenues	$ 22,334	$ 59,215	$ 103,269
Product sales
Segment Reporting Information [Line Items]
Total revenues	22,334	59,215	101,423
Product sales | McKesson Corporation
Segment Reporting Information [Line Items]
Total revenues	5,758	14,900	26,794
Product sales | Cardinal Health
Segment Reporting Information [Line Items]
Total revenues	5,155	15,088	25,413
Product sales | AmerisourceBergen
Segment Reporting Information [Line Items]
Total revenues	3,155	12,059	18,620
Product sales | QuVa Pharma
Segment Reporting Information [Line Items]
Total revenues	3,117	3,252	2,788
Product sales | Others
Segment Reporting Information [Line Items]
Total revenues	5,149	13,916	27,808
License revenue
Segment Reporting Information [Line Items]
Total revenues	$ 0	$ 0	$ 1,846