Inventory (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Inventories
Raw materials	$ 9,689,172	$ 11,304,265
Work-in-process	131,492	304,783
Finished goods	3,505,210	4,306,585
Reserve for excess and obsolete inventory	(2,319,622)	(4,430,872)
Total inventory	$ 10,993,209	$ 11,484,761