CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)
Dec. 31, 2014
Dec. 31, 2013
Customer deposits, allowance for doubtful accounts $ 583,836 $ 585,955
Accounts receivable, allowance for doubtful accounts 44,002,810 60,232,453
Accounts payable 8,260,681 11,264,939
Accrued payroll and welfare expenses 116,577,317 102,632,157
Income tax payable 117,593,159 98,685,965
Other tax payable 49,390,175 40,000,505
Amounts due to related parties 7,356,186 5,535,512
Advance from customers and deferred revenue 19,013,041 24,617,144
Liability for exclusive rights, current   8,967,972
Other current liabilities 85,836,572 62,466,610
Deferred tax liabilities, non-current 28,203,218 29,900,565
Ordinary shares, par value (in dollars per share) $ 0.001 $ 0.001
Ordinary shares, shares authorized (in shares) 1,000,000,000 1,000,000,000
Ordinary shares, shares issued (in shares) 142,123,368 137,816,482
Ordinary shares, shares outstanding (in shares) 142,123,368 137,816,482
Consolidated VIEs without recourse    
Accounts payable 600,735 1,505,942
Accrued payroll and welfare expenses 44,321,824 29,309,329
Income tax payable 28,337,431 28,793,459
Other tax payable 16,032,365 11,188,055
Amounts due to related parties 4,175,247 2,383,293
Advance from customers and deferred revenue 5,073,492 7,150,344
Liability for exclusive rights, current 0 8,967,972
Other current liabilities 36,291,161 9,917,349
Deferred tax liabilities, non-current $ 469,579 $ 655,563