Goodwill and intangible assets (Details 1) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Less: Accumulated amortization	$ (775)	$ (562)
Intangible assets, net	$ 730	1,608
Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated remaining useful life	6 years
Intangible assets, gross	$ 1,440	2,105
Intangible assets, net	$ 712
Software and website development [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated remaining useful life	1 year
Intangible assets, gross	$ 65	$ 65
Intangible assets, net	$ 18