Basis of Presentation (Tables)

9 Months Ended

Sep. 30, 2021

Basis of Presentation [Abstract]

Schedule of revenue disaggregated by revenue source

Revenue disaggregated by revenue source for the three and nine months ended September 30, 2021 and 2020 consists of the following (in thousands); revenue excludes sales and usage-based taxes when or if it has been determined that we are acting as a pass-through agent: 

	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Product sales	$	805	$	1,538	$	3,273	$	3,760
Royalties		2,467		2,212		6,766		6,536
Total revenue	$	3,272	$	3,750	$	10,039	$	10,296