Property, plant and equipment (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Property, plant and equipment
Property, plant and equipment, gross	$ 23,780,168		$ 24,570,233
Less accumulated depreciation	2,151,625		1,722,379
Property, plant and equipment, net	21,628,543		22,847,854
Depreciation expense	561,541	239,577
Land and improvements
Property, plant and equipment
Property, plant and equipment, gross	2,976,654		3,049,765
Buildings and improvements
Property, plant and equipment
Property, plant and equipment, gross	18,720,448		19,788,447
Equipment
Property, plant and equipment
Property, plant and equipment, gross	1,333,028		1,306,597
Construction in progress
Property, plant and equipment
Property, plant and equipment, gross	$ 750,038		$ 425,424