Concentration of Risk, Segment and Geographic Information (Tables)

12 Months Ended

Dec. 31, 2017

Concentration Of Risk Segment And Geographic Information [Abstract]

Revenue by Geographical Region

Revenue attributed to the following geographic regions was as follows (in thousands) based on the location of the licensees:

	Year Ended December 31,
	2017		2016		2015
United States	$	1,654	$	3,822	$	10,685
Europe		50,936		1,642		44,662
Asia Pacific		100		100		100
Total	$	52,690	$	5,564	$	55,447