RESTRICTED CASH (Details) ¥ in Thousands, $ in Thousands |
Dec. 31, 2017
CNY (¥)
|
Dec. 31, 2017
USD ($)
|
Dec. 31, 2016
CNY (¥)
|
|---|---|---|---|
| Restricted Cash and Cash Equivalents Items [Line Items] | |||
| Restricted Cash and Cash Equivalents, Current | ¥ 563,986 | $ 86,683 | ¥ 518,494 |