Basis of Presentation (Tables)

6 Months Ended

Jun. 30, 2020

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, 2020 and 2019 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,
	2020		2019		2020		2019
Product sales	$	1,172	$	2,020	$	2,222	$	3,641
Royalties		2,215		2,205		4,324		3,956
Total revenue	$	3,387	$	4,225	$	6,546	$	7,597