Segment Information (Details) (USD $)
12 Months Ended
Dec. 31, 2014
segment
Dec. 31, 2013
segment
Dec. 31, 2012
segment
Segment Information      
Number of operating segments 2 5 5
Segment Information      
Revenues $ 904,498,793 $ 731,078,833 $ 462,439,368
Cost of revenues (306,133,210) (274,035,806) (203,170,685)
Selling, general and administrative expenses (545,491,718) (400,947,001) (336,873,524)
Other operating income 8,786,891 4,917,642 6,475,023
Income (loss) from operations 61,660,756 61,013,668 (71,129,818)
Interest expense (5,325,474) (192,566)  
Interest income 3,210,328 2,179,547 1,606,462
Other income (expense), net 3,857,539 (1,051,215) (732,870)
Income (loss) before taxes and equity in affiliates 63,403,149 61,949,434 (70,256,226)
Income tax benefit (expense) (14,900,793) (13,676,994) (1,168,654)
Income (loss) before equity in affiliates 48,502,356 48,272,440 (71,424,880)
Income from equity in affiliates 3,834,802 2,813,849 375,509
Net income (loss) 52,337,158 51,086,289 (71,049,371)
Operating Segment | Real Estate Online Services      
Segment Information      
Revenues 495,862,635 335,410,902 169,755,893
Cost of revenues (51,129,730) (63,990,693) (54,117,692)
Selling, general and administrative expenses (365,150,431) (210,576,230) (146,997,279)
Other operating income 2,525,496 599,894 153,340
Income (loss) from operations 82,107,970 61,443,873 (31,205,738)
Interest income 1,316,203 1,082,287 257,204
Other income (expense), net 35,799 (1,185,121) (1,979,450)
Income (loss) before taxes and equity in affiliates 83,459,972 61,341,039 (32,927,984)
Income tax benefit (expense) (15,545,964) (5,447,524) 2,329,338
Income (loss) before equity in affiliates 67,914,008 55,893,515 (30,598,646)
Income from equity in affiliates (223,389) (69,194) (881)
Net income (loss) 67,690,619 55,824,321 (30,599,527)
Operating Segment | Real Estate Brokerage Services      
Segment Information      
Revenues 283,367,930 280,776,816 208,284,503
Cost of revenues (204,101,162) (168,624,507) (114,667,241)
Selling, general and administrative expenses (64,337,955) (74,728,461) (92,291,838)
Other operating income 2,223,460 1,647,257 2,982,861
Income (loss) from operations 17,152,273 39,071,105 4,308,285
Interest income 1,099,825 819,925 425,714
Other income (expense), net (68,069) 87,270 84,937
Income (loss) before taxes and equity in affiliates 18,184,029 39,978,300 4,818,936
Income tax benefit (expense) (5,083,029) (10,000,257) (4,589,892)
Income (loss) before equity in affiliates 13,101,000 29,978,043 229,044
Income from equity in affiliates 118,651 343,561 195,874
Net income (loss) 13,219,651 30,321,604 424,918
Operating Segment | Real Estate Information and Consulting Services      
Segment Information      
Revenues 82,679,298 76,683,188 54,517,612
Cost of revenues (25,153,090) (14,526,318) (10,783,472)
Selling, general and administrative expenses (59,703,161) (58,026,755) (53,977,975)
Other operating income 3,301,932 1,950,223 2,481,255
Income (loss) from operations 1,124,979 6,080,338 (7,762,580)
Interest income 691,003 222,898 624,817
Other income (expense), net 657,952 (479,313) (59,136)
Income (loss) before taxes and equity in affiliates 2,473,934 5,823,923 (7,196,899)
Income tax benefit (expense) (236,440) (3,606,417) 623,227
Income (loss) before equity in affiliates 2,237,494 2,217,506 (6,573,672)
Income from equity in affiliates 1,761,582 312,119 (14,933)
Net income (loss) 3,999,076 2,529,625 (6,588,605)
Operating Segment | Community Value-added Services      
Segment Information      
Selling, general and administrative expenses (15,828,009)    
Income (loss) from operations (15,828,009)    
Interest income 6,124    
Income (loss) before taxes and equity in affiliates (15,821,885)    
Income tax benefit (expense) 3,932,057    
Income (loss) before equity in affiliates (11,889,828)    
Net income (loss) (11,889,828)    
Operating Segment | Other Services      
Segment Information      
Revenues 42,588,930 38,207,927 29,881,360
Cost of revenues (25,749,228) (26,894,288) (23,602,280)
Selling, general and administrative expenses (14,662,201) (12,404,049) (10,544,345)
Other operating income 736,003 720,268 857,567
Income (loss) from operations 2,913,504 (370,142) (3,407,698)
Interest income 78,608 51,944 55,895
Other income (expense), net (8,987) (11,837) (446)
Income (loss) before taxes and equity in affiliates 2,983,125 (330,035) (3,352,249)
Income tax benefit (expense) (169,368) (588,344) 468,673
Income (loss) before equity in affiliates 2,813,757 (918,379) (2,883,576)
Income from equity in affiliates (367,621) (9,320) 195,449
Net income (loss) 2,446,136 (927,699) (2,688,127)
Non-allocated      
Segment Information      
Selling, general and administrative expenses (25,809,961) (45,211,506) (33,062,087)
Income (loss) from operations (25,809,961) (45,211,506) (33,062,087)
Interest expense (5,325,474) (192,566)  
Interest income 18,565 2,493 242,832
Other income (expense), net 3,240,844 537,786 1,221,225
Income (loss) before taxes and equity in affiliates (27,876,026) (44,863,793) (31,598,030)
Income tax benefit (expense) 2,201,951 5,965,548  
Income (loss) before equity in affiliates (25,674,075) (38,898,245) (31,598,030)
Income from equity in affiliates 2,545,579 2,236,683  
Net income (loss) $ (23,128,496) $ (36,661,562) $ (31,598,030)