Goodwill and intangible assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Schedule of Intangible assets and goodwill
Goodwill, Balance	$ 1,496	$ 1,496
Goodwill, Additions (disposals)
Goodwill, Balance	$ 1,496	$ 1,496
Intangible assets, Balance	1,608	$ 1,714
Intangible assets, Disposals	$ (179)
Intangible assets, Additions		$ 354
Intangible assets, Impairment	$ (472)	(135)
Intangible assets, Amortization	(227)	(325)
Intangible assets, Balance	$ 730	$ 1,608