ACCOUNTS RECEIVABLE (Classification of Accounts Receivable) (Details) - CNY (¥)
¥ in Thousands
Dec. 31, 2017
Dec. 31, 2016
Accounts receivable, net - current portion ¥ 216,700 ¥ 97,374
Accounts receivable, net - non-current portion 14,582 1,176
Total accounts receivable, net ¥ 231,282 ¥ 98,550