Loans receivable, net (Additional Information) (Details) |
Dec. 31, 2017 |
|---|---|
| Debt Instrument, Interest Rate, Stated Percentage | 5.00% |
| Minimum [Member] | |
| Debt Instrument, Interest Rate, Stated Percentage | 12.00% |
| Maximum [Member] | |
| Debt Instrument, Interest Rate, Stated Percentage | 16.00% |