Line of credit (Details Textual) (USD $) In Thousands, except Per Share data, unless otherwise specified					6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2014 Venture Champion Asia Limited [Member]	Jun. 30, 2014 Venture Champion Asia Limited [Member] Credit Agreement Warrant [Member]	May 06, 2014 Venture Champion Asia Limited [Member] Credit Agreement Warrant [Member]
Line of Credit Facility [Line Items]
Line of cerdit, initiation day					May 06, 2014
Line of credit facility, description					Credit Agreement
Line of credit facility, unsecured indebtedness, current amount					$ 2,000
Line of credit facility, unsecured indebtedness, maximum amount					2,352
Line of credit facility period					18 months
Original issue discount, percentage					15.00%
Number of common shares callable by warrants					10,909
Warrant coverage, maximum percentage					50.00%
Exercise price	$ 0.0289	$ 0.0289	$ 0.0252	$ 0.0269	$ 0.0275
Expected term						3 years
Initial fair value of warrants							245
Fair value of warrants booked as interest expense at period end						$ 245