Inventories (Details 1) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Inventory valuation allowance, beginning of the period	$ 2,286,297	$ 709,374
Obsolete inventory sold	(48,055)	0
Additional inventory provision	0	1,576,923
Inventory valuation allowance, end of period	$ 2,238,242	$ 2,286,297