STOCK-BASED COMPENSATION (Details 3) - Jun. 30, 2015 - Employee Stock Purchase Plan - USD ($) $ in Thousands	Total
Employee Stock Purchase Plan
Purchase period	6 months
Fair value of the company's stock taken for purchase price calculation (as a percent)	85.00%
Maximum amount of deduction from payroll	$ 7,500
Common Class A
Employee Stock Purchase Plan
Shares reserved for future issuance	1,833,857
Minimum
Employee Stock Purchase Plan
Amount to be deducted from the payroll (as a percent)	1.00%
Maximum
Employee Stock Purchase Plan
Amount to be deducted from the payroll (as a percent)	15.00%