CASH AND CASH EQUIVALENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash and Cash Equivalents [Abstract]
Cash	$ 46,616	$ 63,995
Cash equivalents:
Money market funds	81,541	44,499
Total cash and cash equivalents	$ 128,157	$ 108,494	$ 86,554	$ 35,651