Other Income (Expenses) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Other Income Net [Line Items]
Other income	$ 93,819	$ 114,623	$ (79,596)
Government subsidies
Other Income Net [Line Items]
Other income	95,128	0	0
Gain on sale of scraps
Other Income Net [Line Items]
Other income	0	13,520	16,145
Donation
Other Income Net [Line Items]
Other income	0	0	(41,872)
Other
Other Income Net [Line Items]
Other income	$ (1,309)	$ 101,103	$ (53,869)