Basis of Presentation (Tables)

3 Months Ended

Mar. 31, 2020

Basis of Presentation [Abstract]

Schedule of revenue disaggregated by revenue source

Revenue disaggregated by revenue source for the three months ended March 31, 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 March 31,
	2020		2019
Product sales	$	1,050	$	1,621
Royalties		2,109		1,751
Total revenue	$	3,159	$	3,372