Property, plant and equipment (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Property, plant and equipment
Property, plant and equipment, gross	$ 10,928	$ 9,877
Less accumulated depreciation	2,153	1,686
Property, Plant and Equipment, Net	8,775	8,191
Land and improvements
Property, plant and equipment
Property, plant and equipment, gross	609	699
Buildings and improvements
Property, plant and equipment
Property, plant and equipment, gross	6,446	6,351
Equipment
Property, plant and equipment
Property, plant and equipment, gross	3,873	2,816
Construction in progress
Property, plant and equipment
Property, plant and equipment, gross	$ 0	$ 10