FAIR VALUE MEASUREMENT	12 Months Ended
FAIR VALUE MEASUREMENT	Dec. 31, 2017
FAIR VALUE MEASUREMENT
FAIR VALUE MEASUREMENT	13.FAIR VALUE MEASUREMENT Measured or disclosed at fair value on a recurring basis The Group measured its financial assets and liabilities, including cash equivalents, term deposits, restricted cash, accounts receivable, amounts due from related parties, other receivables and other payables on a recurring basis as of December 31, 2016 and 2017. Cash and cash equivalents, term deposits and restricted cash are classified within Level 1 of the fair value hierarchy because they are valued based on the quoted market price in an active market. The carrying amounts of accounts receivables and amounts due from related parties approximate their fair values due to their short-term maturity. Measured or disclosed at fair value on a non-recurring basis The Group measures goodwill at fair value on a non-recurring basis when it is annually evaluated or whenever events or changes in circumstances indicate that carrying amount of a reporting unit exceeds its fair value as a result of the impairment assessments. The Group measures the purchase price allocation at fair value on a non-recurring basis as of the acquisition dates. The Group continually reviews its long-term investments to determine whether a decline in fair value to below the carrying value is other-than-temporary. The primary factors the Group considers in its determination are the duration and severity of the decline in fair value; the financial condition, operating performance and the prospects of the equity investee; and other company specific information such as recent financing rounds. If the decline in fair value is deemed to be other-than-temporary, the carrying value of the equity investee is written down to fair value.

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.