Business Segments - Summary of revenue by product group (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]
Revenue:	$ 6,027	$ 4,314	$ 19,411	$ 13,720
Operating Segments \| Biometrics
Segment Reporting Information [Line Items]
Revenue:	5,510	3,803	17,720	11,997
Operating Segments \| Imaging
Segment Reporting Information [Line Items]
Revenue:	369	341	1,065	986
Operating Segments \| DSL royalties
Segment Reporting Information [Line Items]
Revenue:	$ 148	$ 170	$ 626	$ 737

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

Name:	us-gaap_SalesRevenueNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration