SHARE-BASED COMPENSATION (Details 2) (Options)
 12 Months Ended 0 Months Ended 12 Months Ended
Dec. 31, 2013
USD ($)
Dec. 31, 2013
CNY
Dec. 31, 2012
CNY
Dec. 31, 2011
CNY
Dec. 31, 2013
Minimum
USD ($)
Dec. 31, 2012
Minimum
USD ($)
Dec. 31, 2011
Minimum
USD ($)
Dec. 31, 2013
Maximum
USD ($)
Dec. 31, 2012
Maximum
USD ($)
Dec. 31, 2011
Maximum
USD ($)
Jul. 08, 2013
Employees
USD ($)
May 21, 2012
Employees
USD ($)
Jun. 20, 2011
Employees
USD ($)
Dec. 31, 2013
Employees
USD ($)
Dec. 31, 2013
Employees
CNY
Dec. 31, 2012
Employees
USD ($)
Dec. 31, 2012
Employees
CNY
Dec. 31, 2011
Employees
USD ($)
Dec. 31, 2011
Employees
CNY
Dec. 31, 2013
Employees
ADS
USD ($)
Number of options                                        
Outstanding at the beginning of the period (in shares)                           36,514,758 36,514,758 40,285,702 40,285,702      
Granted (in shares) 9,471,008 9,471,008 2,130,000 25,954,666                   9,471,008 9,471,008 2,130,000 2,130,000      
Exercised (in shares)                           (11,277,280) (11,277,280) (2,406,272) (2,406,272)      
Forfeited (in shares)                           (2,304,912) (2,304,912) (3,494,672) (3,494,672)      
Outstanding at the end of the period (in shares) 37,911,574 37,911,574                       32,403,574 32,403,574 36,514,758 36,514,758 40,285,702 40,285,702  
Vested and expected to vest at the end of the period (in shares)                           32,403,574 32,403,574 36,514,758 36,514,758      
Exercisable at the end of the period (in shares)                           17,824,031 17,824,031 15,410,254 15,410,254      
Weighted average Exercise price                                        
Outstanding at the beginning of the period (in dollars per shares)                           $ 0.22   $ 0.33        
Granted (in dollars per shares)         $ 0.24 $ 0.24 $ 0.24 $ 0.41 $ 0.41 $ 0.41       $ 0.24   $ 0.27        
Exercised (in dollars per shares)                           $ 0.20   $ 0.22        
Forfeited (in dollars per shares)                           $ 0.24   $ 0.30        
Outstanding at the end of the period (in dollars per shares)                           $ 0.23   $ 0.22   $ 0.33    
Vested and expected to vest at the end of the period (in dollars per shares)                           $ 0.23   $ 0.22        
Exercisable at the end of the period (in dollars per shares)                           $ 0.21   $ 0.19        
Weighted average remaining contractual term (Years)                                        
Outstanding at the begining of the period                           6 years 9 months 11 days 6 years 9 months 11 days 7 years 8 months 12 days 7 years 8 months 12 days 8 years 6 months 29 days 8 years 6 months 29 days  
Vested and expected to vest at the end of the period                           6 years 9 months 11 days 6 years 9 months 11 days 7 years 8 months 12 days 7 years 8 months 12 days      
Exercisable at the end of the period                           7 years 1 month 28 days 7 years 1 month 28 days 7 years 1 month 28 days 7 years 1 month 28 days      
Outstanding at the end of the period                           6 years 9 months 11 days 6 years 9 months 11 days 7 years 8 months 12 days 7 years 8 months 12 days 8 years 6 months 29 days 8 years 6 months 29 days  
Aggregate intrinsic value                                        
Outstanding at the beginning of the period (in dollars)                           $ 840,000   $ 1,035,000        
Vested and expected to vest at the end of the period (in dollars)                           10,479,000   840,000        
Exercisable at the end of the period (in dollars)                           6,211,000   840,000        
Outstanding at the end of the period (in dollars)                           10,479,000   840,000   1,035,000    
Closing price of ordinary shares (in dollars per share)                           $ 0.56           $ 8.91
Total intrinsic value of stock options exercised                           2,560,000   440,000   3,470,000    
Share-based compensation expense (in CNY or dollars) 1,957,000 11,852,000 16,088,000 26,956,000                                
Unrecognized share-based compensation cost (in CNY or dollars)                           2,117,000 12,818,000          
Period over which unrecognized share-based compensation cost are expected to be recognized         3 months     4 years                        
Assumptions used in calculation of estimated fair value of options                                        
Suboptimal exercise factor                     2.8 2.2 2.2              
Risk-free interest rates (as a percent)                     2.66% 1.73% 2.21%              
Expected volatility (as a percent)                     61.26% 67.50% 71.20%              
Expected dividend yield (as a percent)                     0.00% 0.00% 0.00%              
Weighted average fair value of share option (in dollars per share)                     $ 0.141 $ 0.166 $ 0.236              
Total fair value of options vested                           $ 571,301 3,458,482   2,202,839   36,918,136