CONSOLIDATED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
NET REVENUE	$ 853,766,541	$ 637,093,439	$ 370,531,685
Cost of sales	(764,218,167)	(561,379,767)	(308,429,530)
GROSS PROFIT	89,548,374	75,713,672	62,102,155
Selling expenses	(2,954,460)	(2,485,978)	(2,058,323)
General and administrative expenses	(8,621,494)	(6,650,142)	(5,747,178)
Income from operations	77,972,420	66,577,552	54,296,654
Other income (expenses):
Interest income	547,679	522,722	253,964
Interest expenses	0	(143,779)	(131,106)
Foreign exchange differences	109,638	234,763	(112,443)
Gain on extinguishment of warrant liabilities	73,291	88,777	186,897
Change in fair value of warrants	(124,000)	3,062,575	(1,448,819)
Other income (expenses)	93,819	114,623	(79,596)
Total other income (expenses)	700,427	3,879,681	(1,331,103)
Income before income taxes	78,672,847	70,457,233	52,965,551
Provision for income taxes	(20,730,844)	(17,323,700)	(14,499,576)
NET INCOME	57,942,003	53,133,533	38,465,975
OTHER COMPREHENSIVE INCOME:
Foreign currency translation adjustments	659,754	9,152,577	4,626,336
COMPREHENSIVE INCOME	$ 58,601,757	$ 62,286,110	$ 43,092,311
Net income per share
Basic	$ 1.94	$ 1.78	$ 1.38
Diluted	$ 1.93	$ 1.77	$ 1.34
Weighted average number of shares outstanding
Basic	29,815,943	29,816,871	27,956,451
Diluted	29,965,811	30,076,130	28,671,363