SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Memberships (Details) - Members $ in Thousands	12 Months Ended
Dec. 31, 2016 USD ($) customer	Dec. 31, 2015 USD ($) customer
Memberships
Number of Members \| customer	43	44
Membership fee per member \| $	$ 5	$ 5

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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