INCOME TAXES (Schedule of Income before Income Taxes) (Details) - CNY (¥)
¥ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Taxes [Line Items]      
Income before income taxes ¥ 210,577 ¥ 260,630 ¥ 182,727
PRC [Member]      
Income Taxes [Line Items]      
Income before income taxes 212,227 272,745 200,789
Hong Kong [Member]      
Income Taxes [Line Items]      
Income before income taxes (2,415) (573) (1,908)
Cayman Islands [Member]      
Income Taxes [Line Items]      
Income before income taxes ¥ 765 ¥ (11,542) ¥ (16,154)