Cash, cash equivalents and restricted cash (Details Textual) (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Oct. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
Cash and Cash Equivalents [Line Items]
Cash and Cash Equivalents Including Restricted Cash	$ 5,049
Cash and cash equivalents	5,049	3,443		4,864	3,704
Cash, FDIC Insured Amount	405
Restricted Cash and Cash Equivalent Item, Description	Restricted cash includes $99 held in escrow relating to the sale of the Companys portfolio of medical imaging patents pending reclaim of foreign withholding tax.
Cash Maintenance Provision Limit On Shares			345,012
Amount Released Out Of Restricted Cash	2,000
Convertible Preferred Series A Stock Agreement [Member]
Cash and Cash Equivalents [Line Items]
Other Restricted Assets, Noncurrent	$ 39