Condensed Financial Statements of Parent Company (Detail) - Parent Company's Balance Sheet (USD $)	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Assets
Cash and cash equivalents	$ 40,425,310	$ 15,353,882	$ 16,183,493
Other receivables	30,473,435	13,742,625
Income tax receivable		1,406,653
Total current assets	234,718,825	200,465,063
Investment in subsidiaries	10,149,090	3,741,454
Total assets	476,255,884	441,804,216
Accounts payable	41,115,131	39,077,499
Other payables	38,683,732	39,561,388
Advances from employees	225,835	415,253
Accrued interest-current		395,783
Redeemable common stock (US$0.001 par value, nil and 1,312,500 shares issued and outstanding as of December 31, 2012 and 2011, respectively)	19,784	19,714
Total current liabilities	198,631,481	208,437,530
Due to subsidiaries	55,276	86,213
Unrecognized tax benefits - non-current	12,026,563	14,806,768
Total liabilities	274,498,256	266,303,081
Shareholders’ equity	201,757,628	175,483,192
Total liabilities, redeemable common stock and equity	476,255,884	441,804,216
Condensed Financial Statements of Parent Company [Member] | Redeemable Common Stock [Member]
Assets
Redeemable common stock (US$0.001 par value, nil and 1,312,500 shares issued and outstanding as of December 31, 2012 and 2011, respectively)		32,696,658
Condensed Financial Statements of Parent Company [Member]
Assets
Cash and cash equivalents	30,851	494,340	64,612	964,373
Other receivables	3,154	3,154
Income tax receivable		670
Total current assets	34,005	498,164
Due from subsidiaries	87,643,750	87,643,750
Investment in subsidiaries	188,783,841	159,115,372
Total assets	276,461,596	247,257,286
Accounts payable	465,000	472,164
Other payables	930,282	442,600
Advances from employees		105,000
Accrued interest-current		395,783
Total current liabilities	1,395,282	34,112,205
Due to subsidiaries	12,193,504	4,230,102
Unrecognized tax benefits - non-current	1,892,605	1,727,142
Accrued interest-non current		170,555
Other long term loans	59,222,577	32,803,289
Total liabilities	74,703,968	73,043,293
Shareholders’ equity	201,757,628	174,213,993
Total liabilities, redeemable common stock and equity	276,461,596	247,257,286
Redeemable Common Stock [Member]
Assets
Redeemable common stock (US$0.001 par value, nil and 1,312,500 shares issued and outstanding as of December 31, 2012 and 2011, respectively)		$ 32,696,658