Inventories (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
Components of inventories
Raw materials	$ 2,175,861	$ 1,627,784
Work in process	2,366,133	1,778,650
Finished goods	1,745,578	1,509,606
Inventory gross	6,287,572	4,916,040
Less: reserve for obsolete inventory	(180,957)	(182,482)
Inventory net	$ 6,106,615	$ 4,733,558