Basis of Presentation (Tables)

6 Months Ended

Jun. 30, 2021

Basis of Presentation [Abstract]

Schedule of revenue disaggregated by revenue source

Revenue disaggregated by revenue source for the three and six months ended June 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 June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Product sales	$	1,305	$	1,172	$	2,468	$	2,222
Royalties		2,483		2,215		4,299		4,324
Total revenue	$	3,788	$	3,387	$	6,767	$	6,546