SUMMARY OF PRINCIPAL ACCOUNTING POLICIES (Foreign Currency and Derivative Financial Instruments) (Narrative) (Details) |
Dec. 31, 2017
USD ($)
|
Dec. 31, 2017
CNY (¥)
|
Dec. 31, 2016
USD ($)
|
Dec. 31, 2016
CNY (¥)
|
|---|---|---|---|---|
| Foreign currency [Line Items] | ||||
| Cash and cash equivalents, functional currency equivalent of foreign currency denominated amount | $ 2,017 | ¥ 19,626,332 | $ 20,791,918 | ¥ 14,629,660 |