Business Segments - Summary of revenue by product group (Details 1) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Revenue	$ 5,899	$ 4,041	$ 17,637	$ 12,674
Operating Segments | Biometrics
Segment Reporting Information [Line Items]
Revenue	4,514	3,575	13,241	11,306
Operating Segments | Imaging
Segment Reporting Information [Line Items]
Revenue	1,336	373	4,144	1,069
Operating Segments | DSL royalties
Segment Reporting Information [Line Items]
Revenue	$ 49	$ 93	$ 252	$ 299