Property, plant and equipment (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Property, plant and equipment
Property, plant and equipment, gross	$ 23,693,345		$ 23,693,345		$ 24,570,233
Less accumulated depreciation	2,667,729		2,667,729		1,722,379
Property, plant and equipment, net	21,025,616		21,025,616		22,847,854
Depreciation expense	554,194	525,660	1,065,838	765,237
Land and improvements
Property, plant and equipment
Property, plant and equipment, gross	2,884,462		2,884,462		3,049,765
Buildings and improvements
Property, plant and equipment
Property, plant and equipment, gross	18,325,355		18,325,355		19,788,447
Equipment
Property, plant and equipment
Property, plant and equipment, gross	2,313,515		2,313,515		1,306,597
Construction in progress
Property, plant and equipment
Property, plant and equipment, gross	$ 170,013		$ 170,013		$ 425,424