Properties Held for Sale (Details) (USD $)
12 Months Ended
Dec. 31, 2014
property
Dec. 31, 2013
property
Dec. 31, 2012
property
Properties Held for Sale      
Number of properties obtained in settlement of accounts receivable 30 14 6
Properties held for sale obtained in settlement of accounts receivable $ 7,122,155 $ 6,678,302 $ 970,625
Number of properties transferred for settlement of customer deposit 0 36 0
Properties held for sale transferred in settlement of customer deposit 0 9,928,558 0
Gain (loss) from sale of properties held for sale 0 118,559 45,936
Carrying amount of properties held for sale 34,841,895 15,304,927  
Properties held for sale transferred to property and equipment 0 0 1,281,008
Number of properties acquired   237  
Advance payment for properties to be held for sale $ 51,983,436 $ 60,076,026  
Commercial properties      
Properties Held for Sale      
Number of properties obtained in settlement of accounts receivable 5    
Number of properties held for sale 5    
Number of properties title transfer in process 55 52  
Car parking space properties      
Properties Held for Sale      
Number of properties obtained in settlement of accounts receivable 5 5  
Number of properties held for sale 9 5  
Number of properties title transfer in process   5  
Residential properties      
Properties Held for Sale      
Number of properties obtained in settlement of accounts receivable 20    
Number of properties held for sale 147 44  
Number of properties transferred to held for sale 101    
Number of properties title transfer in process 113 140