Intangible assets amortization expenses (Details) - USD ($) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Intangible assets amortization expenses | ||
| Amortization expenses relating to intangible assets | $ 262,908 | $ 317,908 |
| Impairment loss; | $ 0 | $ 104,544 |